Updated on 2024/03/27

写真a

 
NAKAMURA, Hideki
 
Organization
Graduate School of Environmental Studies Department of Environmental Engineering and Architecture Sustainable Urban Development Professor
Graduate School
Graduate School of Environmental Studies
Graduate School of Engineering
Undergraduate School
School of Engineering
School of Engineering Architecture
Title
Professor
Contact information
メールアドレス
External link

Degree 1

  1. Doctor of Engineering ( 1991.3   The University of Tokyo ) 

Research Interests 1

  1. Traffic flow, Highway planning and design, Traffic safety, Impact of automated driving on traffic flows, Traffic operations

Research Areas 1

  1. Social Infrastructure (Civil Engineering, Architecture, Disaster Prevention) / Civil engineering plan and transportation engineering  / Traffic Engineering, Transportation Planning

Current Research Project and SDGs 3

  1. Highway Capacity and Quality of Service

  2. Planning, design and operation of intersections

  3. Performance-Oriented Road Planning, Design and Traffic Operation

Research History 6

  1. Nagoya University Graduate School of Environmental Studies, Department of Environmental Engineering and Architecture   Graduate School of Environmental Studies, Department of Environmental Engineering and Architecture   Professor

    2014.5

  2. Nagoya University   Green Mobility Collaborative Research Center   Professor

    2011.7 - 2016.3

  3. Nagoya University   Institute of Liberal Arts and Sciences   Professor

    2009.4 - 2012.3

  4. Nagoya University   Graduate School of Engineering, Department of Civil Engineering   Professor

    2007.10 - 2014.4

  5. Nagoya University   Graduate School of Engineering, Department of Geotechnical Engineering   Associate professor

    1996.4 - 2007.9

  6. Minstry of Construction   Public Works Research Institute   Chief Researcher

    1991.4 - 1996.3

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    Country:Japan

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Education 3

  1. The University of Tokyo   Graduate School, Division of Engineering   Department of Civil Engineering

    1988.4 - 1991.3

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    Country: Japan

  2. The University of Tokyo   Graduate School, Division of Engineering   Department of Civil Engineering

    1985.4 - 1987.3

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    Country: Japan

  3. Waseda University   Faculty of Science and Engineering   Department of Civil Engineering

    1980.4 - 1985.3

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    Country: Japan

Professional Memberships 6

  1. Japan Society of Civil Engineers

  2. Japan Society of Traffic Engineers   President

  3. World Conference on transport Research Society   Vice Chair, Scientific Committee

  4. EASTS

  5. International Association of Traffic and Safety Sciences

  6. ITS Japan

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Awards 17

  1. 交通工学研究会 第42回交通工学研究発表会 研究奨励賞

    2022.8   一般社団法人 交通工学研究会  

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    Award type:Award from Japanese society, conference, symposium, etc. 

  2. 交通工学研究会 第39回交通工学研究発表会 研究奨励賞

    2019.8   一般社団法人 交通工学研究会   信号交差点密度を考慮した道路事業便益の算出手法

    柿元祐史・中村英樹

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  3. 交通工学研究会 第33回論文賞

    2019.6   一般社団法人 交通工学研究会   ラウンドアバウトの幾何構造が走行挙動特性に与える影響分析

    吉岡慶祐・中村英樹・下川澄雄・森田綽之

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    Award type:Honored in official journal of a scientific society, scientific journal  Country:Japan

  4. WCTR Topic Area C Best Paper Award, 15th World Conference on Transport Research (WCTR)

    2019.5   World Conference on Transport Research Society   A Model Analysis of the Saturation Flow Rate Influenced by Downstream Conditions

    Zhu, H. and Nakamura, H.

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    Country:India

  5. 土木学会土木計画学研究委員会 平成30年度 優秀研究論文賞

    2018.11   土木学会   幾何構造要因を考慮したラウンドアバウト流入交通容量推定モデル

    神戸信人・張馨・中村英樹・尾高慎二

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    Award type:Honored in official journal of a scientific society, scientific journal  Country:Japan

  6. 交通工学研究会 第38回交通工学研究発表会 研究奨励賞

    2018.8   一般社団法人 交通工学研究会  

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  7. 交通工学研究会 第32回論文賞

    2018.6   一般社団法人 交通工学研究会  

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    Award type:Honored in official journal of a scientific society, scientific journal  Country:Japan

  8. 交通工学研究会 第37回交通工学研究発表会 安全の泉賞

    2017.8   一般社団法人 交通工学研究会  

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  9. 交通工学研究会 第31回論文賞

    2017.6   一般社団法人 交通工学研究会  

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    Award type:Honored in official journal of a scientific society, scientific journal  Country:Japan

  10. 平成27年度 新道路技術会議 優秀技術研究開発賞

    2015.11   新道路技術会議  

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    Country:Japan

  11. 交通工学研究会 第35回交通工学研究発表会 研究奨励賞

    2015.9   一般社団法人 交通工学研究会  

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  12. 交通工学研究会 第32回交通工学研究発表会 研究奨励賞

    2012.9   一般社団法人 交通工学研究会  

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    Award type:Award from Japanese society, conference, symposium, etc.  Country:Japan

  13. Yasoshima Yoshinosuke Prize

    2009.11   8th EASTS International Conference  

  14. 平成20年度 新道路技術会議 優秀技術研究開発賞

    2009.10   国土交通省道路局 新道路技術会議  

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    Country:Japan

  15. JSTE 21st Dissertation Award

    2007.5   Japan Society of Traffic Engineers  

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    Country:Japan

  16. 交通工学研究発表会 研究奨励賞

    1998  

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    Country:Japan

  17. 国際交通安全学会賞 論文部門

    1994  

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    Country:Japan

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Papers 406

  1. Modelling discharge flows at signalised intersections with adjustment of downstream effects

    Zhu H., Nakamura H.

    TRANSPORTMETRICA A-TRANSPORT SCIENCE     2021.3

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    Language:Japanese   Publisher:Transportmetrica A: Transport Science  

    Former studies revealed that before spillbacks happen intersection capacities can still be greatly affected by downstream queues and signals. However, there is no methodology reasonably accounting for this effect. This research aims to propose adjustment factor models (Adj models) for both saturation flow rate (SFR) and start-up lost time (SLT) in through lane groups considering downstream conditions. An improved cell transmission model is created to build a simulation platform that can well reproduce the downstream influence. By the experimental data, Adj models are derived through heuristic optimisation based regression analyses. Proposed adjustment factors are governed by common traffic indicators. Sensitivity analyses proved that approaches with high volumes, short segment lengths, large green ratios, positive offset, or large cycle lengths are more easily affected by downstream conditions. Through the validation, it is proved that the estimation error of SFR and SLT can be significantly reduced by the proposed adjustment factors.

    DOI: 10.1080/23249935.2021.1895360

    Web of Science

    Scopus

  2. Investigating the Efficiency and Safety of Signalized Intersections Under Mixed Flow Conditions of Autonomous and Human-Driven Vehicles

    Pan Ang, Zhang Xin, Nakamura Hideki, Alhajyaseen Wael

    ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING   Vol. 45 ( 10 ) page: 8607 - 8618   2020.10

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    Language:Japanese   Publishing type:Research paper (scientific journal)   Publisher:Arabian Journal for Science and Engineering  

    Field experiments of autonomous driving systems have already been started in several countries around the world. However, investigations on the performance of signalized intersections under the mixed flow condition of autonomous vehicle (AV) and human-driven vehicle (HDV) are still very limited, especially in terms of considering the interaction between vehicles. This study aims at developing a methodology to evaluate the efficiency and safety performance of signalized intersections under the conditions of AV mixed flows. If AVs are set aggressively such as small critical gap acceptance thresholds, approach capacity of signalized intersections may increase. However, the aggressive driving maneuver and the misjudgment by human drivers to AV may lead to some potential safety risks. On the other hand, if AVs are set conservatively to ensure large safety margins, for example by setting large critical gap thresholds or a longer following headway, a significant drop in the capacity is expected while the safety improvements may not be insured since extra delays will be imposed on HDVs which may induce risky behavior. This study finds that AVs with either excessively aggressive or conservative settings will lead to waste of capacity or potential safety hazard. AVs with aggressive settings will enable them to accept a short gap or lag, while AVs with conservative settings will increase the waiting time of the following HDVs, which may induce aggressive driving behavior. Both types of AV settings may contribute to safety risks represented by short time-to-collision and short post encroachment time.

    DOI: 10.1007/s13369-020-04810-1

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    Scopus

  3. Initial comparative analysis of international practice in road traffic signal control

    Tang K.

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections     page: 285 - 310   2019.1

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    Publishing type:Research paper (scientific journal)   Publisher:Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  

    DOI: 10.1016/B978-0-12-815302-4.00015-7

    Scopus

  4. Principles of road traffic signal control

    Boltze M.

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections     page: 7 - 17   2019.1

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    Publishing type:Research paper (scientific journal)   Publisher:Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  

    DOI: 10.1016/B978-0-12-815302-4.00002-9

    Scopus

  5. Japan

    Nakamura H.

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections     page: 163 - 184   2019.1

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    Publishing type:Research paper (scientific journal)   Publisher:Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  

    DOI: 10.1016/B978-0-12-815302-4.00010-8

    Scopus

  6. An Analysis of Heavy Vehicle Impact on Roundabout Entry Capacity in Japan

    Kang Nan, Nakamura Hideki

    INTERNATIONAL SYMPOSIUM ON ENHANCING HIGHWAY PERFORMANCE (ISEHP), (7TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE, 3RD INTERNATIONAL SYMPOSIUM ON FREEWAY AND TOLLWAY OPERATIONS)   Vol. 15   page: 308 - 318   2016

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    Language:Japanese   Publisher:Transportation Research Procedia  

    Impact of heavy vehicles on roundabout entry capacity is generally considered through a heavy vehicle adjustment factor fHV which is calculated by heavy vehicle percentage and passenger car equivalent (PCE hereafter) value. The PCE value of trucks is generally set as 2.0 and estimated based on several considerations such as entry capacity and move-up time. All of these considerations are influenced by local driver behavior and geometry conditions. Thus, this paper aims to estimate entry capacity considering the characteristics of heavy vehicle behavior in Japan by microscopic simulation. Then based on the simulation results, the PCE value is also examined. Through the simulation study it is found that entry capacity is reduced when heavy vehicle percentage increases. Moreover, estimated PCE results show that the PCE value of entry flow increases when circulating flow increases but decreases when circulating flow is in high level. Also it is found that PCE of entry flow is lower than that of circulating flow which has priority at roundabouts.

    DOI: 10.1016/j.trpro.2016.06.026

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    Scopus

  7. Functionally Hierarchical Road Classification Considering the Area Characteristics for the Performance-oriented Road Planning

    Goto Azusa, Nakamura Hideki

    INTERNATIONAL SYMPOSIUM ON ENHANCING HIGHWAY PERFORMANCE (ISEHP), (7TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE, 3RD INTERNATIONAL SYMPOSIUM ON FREEWAY AND TOLLWAY OPERATIONS)   Vol. 15   page: 732 - 748   2016

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    Language:Japanese   Publisher:Transportation Research Procedia  

    This study aims to find out the necessary target travel speeds of roads in functionally hierarchical network which can achieve the target travel times for connecting centers with five different functions, considering the distribution of centers in the subjective area. In this paper, hierarchical road classification scenarios which consists of target travel speeds and road spacings are developed for differentiating road functions. Then travel times under the certain scenario are numerically calculated by an approximate method. Here, the calculation is based on a combination of hypothetical grid network and the actual motorway network. Finally, an application study of Tokaido region in Japan and southwest region in Germany demonstrated the impact of hierarchical road classification scenario on the achievement of the target travel time between centers in different categories.

    DOI: 10.1016/j.trpro.2016.06.061

    Web of Science

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  8. An Estimation Method of Roundabout Entry Capacity Considering Pedestrian Impact

    Kang Nan, Nakamura Hideki

    9TH INTERNATIONAL CONFERENCE ON TRAFFIC AND TRANSPORTATION STUDIES (ICTTS 2014)   Vol. 138   page: 460 - 469   2014

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  9. A Modified Social Force Model for Pedestrian Behavior Simulation at Signalized Crosswalks

    Zeng Weiliang, Nakamura Hideki, Chen Peng

    9TH INTERNATIONAL CONFERENCE ON TRAFFIC AND TRANSPORTATION STUDIES (ICTTS 2014)   Vol. 138   page: 521 - 530   2014

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  10. Lane Utilization Analysis of Shared Left-turn Lane Based on Saturation Flow Rate Modeling

    Chen Peng, Nakamura Hideki, Asano Miho

    8TH INTERNATIONAL CONFERENCE ON TRAFFIC AND TRANSPORTATION STUDIES (ICTTS)   Vol. 43   page: 178 - 191   2012

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  11. A Method for Evaluating the Functional Hierarchy of Road Networks by using Road Use Characteristic Indices

    SEKIHARA Toshihiro, KAKIMOTO Yuji, NAKAMURA Hideki, IRYO Miho, ZHANG Xin

    JSTE Journal of Traffic Engineering   Vol. 9 ( 2 ) page: A_69 - A_78   2023.2

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    Language:Japanese   Publisher:Japan Society of Traffic Engineers  

    <p>The concept of a functional hierarchical road network is important as one of the solutions to the road traffic problems that still occur in Japan, where the road network has been steadily developed. This study aims to propose a method to evaluate in which degree of functional hierarchy the road network is being used. In a virtual road network with three levels of hierarchy, the shortest routes are searched under the free flow conditions, and the road use characteristic indices are calculated such as trip lengths and use rates of each hierarchical level. Based on the conditions of the road network represented by these index values, a method to evaluate its functional hierarchy in four degrees is proposed. As a case study, the degree of hierarchy was calculated for the road networks in southern Gifu and western Shizuoka. The results revealed that the current evaluations of the functional hierarchy in these areas were low, and that the mid-level roads are required for improving the current situation.</p>

    DOI: 10.14954/jste.9.2_a_69

    CiNii Research

  12. Analysis of the Relationship between the Functionally Hierarchical Characteristics of Road Networks and Road Structure Conditions

    TOMINAGA Masahiro, KAKIMOTO Yuji, NAKAMURA Hideki, SEKIHARA Toshihiro

    JSTE Journal of Traffic Engineering   Vol. 9 ( 2 ) page: A_35 - A_43   2023.2

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    Language:Japanese   Publisher:Japan Society of Traffic Engineers  

    <p>The road network in Japan has been steadily developed until today, however, some issues are remaining such as low travel speeds on main roads and through-passing traffics into minor streets in residential areas. This is considered because of insufficient consideration of the hierarchical function of each road at the planning stage. For this reason, it is necessary to reconsider the road network from the functional hierarchy perspective of whether each road is hierarchically being used according to its target function. Therefore, the objective of this study is to clarify influencing factors of the functional hierarchy based on questionnaire surveys for experts in road design and planning. As a result, it was found that road conditions such as the trip length and the travel speed affect the functional hierarchy, and the combination of them is necessary for proper evaluation of the functional hierarchy.</p>

    DOI: 10.14954/jste.9.2_a_35

    CiNii Research

  13. Analysis of factors affecting differences in off-peak travel speeds on arterial roads in Japan and abroad

    INAMOTO Yuichi, ZHANG Xin, NAKAMURA Hideki

    Proceedings of the Conference of Japan Society of Traffic Engineers   Vol. 43 ( 0 ) page: 403 - 410   2023

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    Language:Japanese   Publisher:Japan Society of Traffic Engineers  

    DOI: 10.14954/jsteproceeding.43.0_403

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  14. Defensive or competitive Autonomous Vehicles: Which one interacts safely and efficiently with pedestrians?

    Zhu H., Alhajyaseen W., Iryo-Asano M., Nakamura H., Dias C.

    Physica A: Statistical Mechanics and its Applications   Vol. 606   2022.11

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    Publisher:Physica A: Statistical Mechanics and its Applications  

    The emergence of Autonomous Vehicles (AVs) could provoke unexpected challenges in urban traffic environments. One such crucial challenge is the conflicts between pedestrians and AVs, particularly on unsignalized mid-block crosswalks (UMC), where pedestrians are exposed to the AV flow. This study investigates the efficiency and safety performance of a UMC in the presence of both AVs and pedestrians considering the diversities in their behaviors. Through empirical analyses, two pedestrians’ crossing decision models are built and four groups of speed profiles are classified. Meanwhile, based on previous literature, defensive and competitive driving strategies are assumed for AVs. The simulation is implemented on an agent-based framework that can dynamically reproduce the kinematic interactions between pedestrians and vehicles. Results indicated that with a reasonable safety margin (2.5 s), percentages of low post encroachment time events for competitive AVs with different pedestrian types are smaller than defensive AVs with differences of 0.2% to 2.9%. The average delays of competitive AVs for all pedestrian types are smaller than defensive AVs with a maximum estimated difference of 39 s. Moreover, the analysis showed that lowering the speed limit may reduce the crash rate of competitive AV up to 0%. It is also found that the pedestrians who make reckless crossing decisions and change their speed drastically during the crossing process are more likely to incur crashes with competitive AVs. Therefore, if pedestrian behaviors can be regulated reasonably, competitive AVs with appropriate parameter settings are most suitable for UMC in the future.

    DOI: 10.1016/j.physa.2022.128083

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    Scopus

  15. Can automated driving prevent crashes with distracted Pedestrians? An exploration of motion planning at unsignalized Mid-block crosswalks

    Zhu H., Han T., Alhajyaseen W.K.M., Iryo-Asano M., Nakamura H.

    Accident Analysis and Prevention   Vol. 173   page: 106711   2022.8

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    Language:English   Publisher:Accident Analysis and Prevention  

    Pedestrian distraction may provoke severe difficulties in automated vehicle (AV) control, which may significantly affect the safety performance of AVs, especially at unsignalized mid-block crosswalks (UMCs). However, there is no available motion-planning model for AVs that considers the effect of pedestrian distraction on UMCs. This study aims to explore innovative approaches for safe and reasonable automated driving in response to distracted pedestrians with various speed profiles at UMCs. Based on two common model design concepts, two new models are established for AVs: a rule-based model that solves motion plans through a fixed calculation procedure incorporating several optimization models, and a learning-based model that replaces the deterministic optimization process with policy-gradient reinforcement learning. The developed models were assessed through simulation experiments in which pedestrian speed profiles were defined using empirical data from field surveys. The results reveal that the learning-based model has outstanding safety performance, whereas the rule-based model leads to remarkable safety problems. For distracted pedestrians with significant crossing-speed changes, rule-based AVs lead to a 5.1% probability of serious conflict and a 1.4% crash probability. The learning-based model is oversensitive to risk and always induces high braking rates, which results in unnecessary efficiency loss. To overcome this, a hybrid model based on the learning-based model was developed, which introduces a rule-based acceleration value to regularize the action space of the proposed learning-based model. The results indicate that the hybrid approach outperforms the other two models in preventing crash hazards from distracted pedestrians by employing appropriate braking behaviors. The high safety performance of the hybrid models can be attributed to the spontaneous slowing down of the vehicle that initiates before detecting pedestrians on UMCs. Although such a cautious driving pattern leads to extra delay, the time cost of the hybrid model is acceptable considering the significant improvements in ensuring pedestrian safety.

    DOI: 10.1016/j.aap.2022.106711

    Web of Science

    Scopus

    PubMed

  16. Investigating driver reactions to movements of autonomous vehicle in permitted right turn through driving simulator experiments

    Zhu H., Zhu S., Iryo-Asano M., Nakamura H.

    Transportation Research Part F: Traffic Psychology and Behaviour   Vol. 89   page: 385 - 398   2022.8

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    Publisher:Transportation Research Part F: Traffic Psychology and Behaviour  

    Traffic safety has always been a hot topic for human-driven (HDV) and autonomous vehicles (AV) mixed flow. The conflict between permitted right-turn vehicles (PRT) and opposing through vehicles (TH) at signalized intersections (left-handed traffic) is extraordinarily critical. AVs with aggressive behaviors are able to accept short gap time without losing safety. However, such a turning maneuver may lead to dangerous feelings and cause unexpected reactions of approaching drivers. This study aims to investigate and model drivers’ reactions in TH movements to PRT AVs considering the trust degree of drivers to AVs. Questionnaire surveys and driving simulator experiments were conducted for 41 participants. Results reveal that the right turn timing of PRT AV will significantly influence drivers’ reactions. Basically, TH drivers will brake with a high probability under the situation of small expected post encroachment time (PET). It is also found that female drivers and drivers with low trust in AVs are more vigilant to PRT AVs than other drivers. Based on this finding a two-layer model for reproducing TH drivers’ reactions to PRT AVs is proposed. The first layer is to determine the braking decision and the second layer is to calculate the parameters of braking behaviors (brake lag, braking time, and speed drop). The significance and coefficients variables in these models proved that the trust in AV will influence drivers’ decisions and braking behaviors (brake lag and braking time). The more the drivers trust AVs, the smaller the expected PET to AVs they can accept for passing without braking, and the more gently they will brake (longer brake lag and shorter braking time) due to the cutting in of PRT AVs. This effect will become significant after drivers have experienced several interactions with AVs.

    DOI: 10.1016/j.trf.2022.06.018

    Web of Science

    Scopus

  17. A novel hierarchical cooperative merging control model of connected and automated vehicles featuring flexible merging positions in system optimization

    Tang Z., Zhu H., Zhang X., Iryo-Asano M., Nakamura H.

    Transportation Research Part C: Emerging Technologies   Vol. 138   2022.5

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    Publisher:Transportation Research Part C: Emerging Technologies  

    Merging sections on freeways are typical bottlenecks for traffic efficiency and safety. The connected and automated vehicles (CAV) technology has great capability in improving traffic performance of merging bottlenecks. Current approaches of system optimal cooperative merging control assume single fixed merging point (CMC-SMP) for on-ramp vehicles to reduce the complexity of their models. Non-fixed merging positions have the potential to further improve merging operations but may lead to the computational explosion. To solve this core contradiction, this study proposes a novel hierarchical system optimal cooperative merging control model considering flexible merging positions (CMC-FMP) to realize safe and efficient merging processes. The upper-level – the tactical planning model is formulated as a non-convex mixed integer quadratically constrained programming, aiming at minimal total travel time in the control zone. It optimizes not only the merging sequence but also vehicles’ critical states in merging processes, such as the state of on-ramp vehicles when they merge. The lower-level - the motion planning model generates feasible trajectories and the next step actions for every vehicle. A Monte Carlo Tree Search-based decomposition algorithm (MCTS-DA) is further designed to improve the computational efficiency of the tactical planning model. Meanwhile, solutions of MCTS-DA are proved to have good optimality compared to the direct solving method. A batch-based scheme is developed to realize real-time control. The results reveal that the average delays of CMC-FMP are remarkably lower than those of CMC-SMP. Especially in low on-ramp ratio scenarios, the difference in improvement can reach 64%. Furthermore, the sensitivity analysis indicates that large safe merging margins and short merging sections are disadvantageous for traffic efficiency for the merging flow controlled by CMC-FMP.

    DOI: 10.1016/j.trc.2022.103650

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  18. Examination of Teardrop Roundabout Geometric Design through a Field Experimental Study

    OKUSHIRO Hiroshi, YOSHIOKA Keisuke, ISHIGURO Yuuki, NAKANE Takeshi, MATSUOKA Toshiaki, SHUDO Takako, ZHANG Xin, NAKAMURA Hideki, ABE Yoshinori, KANBE Nobuto, SHIMOKAWA Sumio

    JSTE Journal of Traffic Engineering   Vol. 8 ( 4 ) page: B_18 - B_25   2022.4

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    Language:Japanese   Publisher:Japan Society of Traffic Engineers  

    DOI: 10.14954/jste.8.4_b_18

    CiNii Research

  19. Efficiency and Safety Evaluation of Left-turn Vehicles and Crossing Pedestrians in Signalized Intersections under the Autonomous Vehicle Mixed Flow Condition

    Pan, A; Zhang, X; Iryo-Asano, M; Nakamura, H

    INTERNATIONAL JOURNAL OF INTELLIGENT TRANSPORTATION SYSTEMS RESEARCH   Vol. 20 ( 1 ) page: 103 - 116   2022.4

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    Language:Japanese   Publisher:International Journal of Intelligent Transportation Systems Research  

    Field experiments of autonomous vehicles (AVs) have been conducted in many countries. However, efficiency evaluation of AV mixed flow and safety evaluation of conflicts between AVs and pedestrians in the real-world case are still limited. This study aims at evaluating the efficiency and safety of left-turn (LT) vehicles and pedestrians in signalized intersections, under the condition of AV mixed flow, by developing a simulation model. Post Encroachment Time (PET) and LT capacity were obtained. Further, gap/lag acceptance behavior and reaction time of LT vehicles were found to be critical parameters that affect efficiency and safety evaluations.

    DOI: 10.1007/s13177-021-00276-z

    Web of Science

    Scopus

  20. An international comparative study on driving attitudes and behaviors based on questionnaire surveys

    Suzuki K., Tang K., Alhajyaseen W., Suzuki K., Nakamura H.

    IATSS Research   Vol. 46 ( 1 ) page: 26 - 35   2022.4

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    Publisher:IATSS Research  

    Road traffic crashes (RTCs) are influenced by a driver's awareness and attitude toward road safety, as well as the socio-economic status, infrastructure development level, traffic status, social system, and traffic safety culture of the area to which the driver belongs. In this study, based on the results of a questionnaire survey conducted in seven countries, the characteristics of each country concerning tolerance for traffic violations, dangerous driving, and acceptance for road safety measures were studied. It was suggested that a high tolerance for traffic violations and dangerous driving might affect traffic violations and RTCs in each country. Additionally, to reduce the tolerance for traffic violations and dangerous driving, the promotion of road safety education, especially among young and male drivers, and stricter regulations and enforcement were suggested.

    DOI: 10.1016/j.iatssr.2021.10.002

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  21. A multi-country survey for collecting and analyzing facts related to road traffic safety: Legislation, enforcement, and education for safer drivers

    Toriumi A., Abu-Lebdeh G., Alhajyaseen W., Christie N., Gehlert T., Mehran B., Mussone L., Shawky M., Tang K., Nakamura H.

    IATSS Research   Vol. 46 ( 1 ) page: 14 - 25   2022.4

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    Publisher:IATSS Research  

    Road traffic safety is a crucial global objective. It is important for every country to review and improve road safety policies and strategies, based on an objective understanding of its own road traffic safety situation in the world. With the aim of contributing to such a review and understanding, this study conducted a multi-country survey to gather information about various facts related to legislation, enforcement, and education, which are designed to achieve safer drivers in nine countries, by using a common format. This paper introduces the results of the survey with a particular focus on legislation and enforcement regarding speed limit violations and red-light-running as well as on education within the driving licensing systems. It highlights variations, in terms of penalty settings and enforcement levels, in different countries; it also examines the training durations necessary for acquiring a driving license and license renewal procedures. In this way, it demonstrates the potential and significance of understanding the relative position of each country in terms of road traffic safety through an international comparison despite its limited information.

    DOI: 10.1016/j.iatssr.2022.01.004

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  22. Road safety and traffic culture from an international perspective

    Nakamura H., Morimoto A.

    IATSS Research   Vol. 46 ( 1 ) page: 1 - 2   2022.4

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  23. Modeling effects of driver safety attitudes on traffic violations in China using the theory of planned behavior

    Tan C., Shi Y., Bai L., Tang K., Suzuki K., Nakamura H.

    IATSS Research   Vol. 46 ( 1 ) page: 63 - 72   2022.4

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    Publisher:IATSS Research  

    Traffic violations are recognized as one of the main causes of traffic accidents and have been found to be closely associated with driver attitudes toward traffic safety. In this study, a modified theory of planned behavior (TPB) was used to model the effects of driver safety attitudes on traffic violations, based on a questionnaire survey of 1505 drivers in China. In light of the strong correlations between the observed items, the items of the TPB components were grouped into several parcels, using an item-parceling method. Parcel-based structural equation modeling was then used to operationalize the modified TPB. The results indicate that the proposed model can accurately predict the occurrence of traffic violations based on the observed items related to driver traffic safety attitudes. It was found that driver attitudes, subjective norm, and perceived behavior control significantly affect traffic violations. For predicting traffic violations, driver attitudes toward traffic safety policies had the greatest influence, followed by driver attitudes toward risky driving behaviors and the attitudes of others toward risky driving behaviors. Finally, suggestions on traffic enforcement and education to reduce traffic violations are proposed based on the results.

    DOI: 10.1016/j.iatssr.2022.02.001

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  24. Investigating the attitudes of Egyptian drivers toward traffic safety

    Timmermans C., Shawky M., Alhajyaseen W., Nakamura H.

    IATSS Research   Vol. 46 ( 1 ) page: 73 - 81   2022.4

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    One of the main pillars for improving road safety in any country is a good understanding of traffic safety culture and the driving behavior of local drivers. The primary aim of this study was to determine whether Egyptian drivers differ in traffic safety attitudes and level of acceptance of risky driving behavior. A questionnaire survey was conducted on the driving cognition of the participants. An exploratory factor analysis was used to assess the number of factors that differentiated the three types of drivers. Then a hierarchical cluster analysis was performed to group the drivers with similar patterns of scores on the factors into clusters. Three driver clusters emerged: The drivers in cluster 1 were “drivers who rigidly followed regulations” (51.7%). The drivers in cluster 2 were “drivers who violated safety precautions” (23.3%). The drivers in cluster 3 were “drivers who had a tendency to violate regulations” (25.0%). A similarity between the social norms and personal attitudes of drivers was found. This can be explained by the high social norm of violating traffic laws, which can lead to more drivers accepting violations. The majority of the older drivers and drivers with no violations or traffic accident on their record in the past 2 years were in cluster 1. Cluster 2 had the highest proportion of young drivers who wore their seat belts and used hands-free phones while driving. Cluster 3 drivers accepted very dangerous violations, such as texting while driving, driving while intoxicated, and driving at very high speeds. They reported significantly more traffic accidents, but no more violations than the other two clusters. The results of this study can be used to improve road safety programs for education and enforcement in Egypt.

    DOI: 10.1016/j.iatssr.2021.11.007

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  25. International analysis on social and personal determinants of traffic violations and accidents employing logistic regression with elastic net regularization

    Shiomi Y., Toriumi A., Nakamura H.

    IATSS Research   Vol. 46 ( 1 ) page: 36 - 45   2022.4

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    While the number of road fatalities is declining in developed countries, it is still increasing globally, especially in middle-and low-income countries. In addition to the driver's individual awareness and attitude toward traffic safety, various factors such as the development of road infrastructure and the legal system may have a significant influence on the occurrence of traffic accidents. Thus, it is essential to consider these factors to enhance traffic safety and achieve Sustainable Development Goal (SDG) Targets of 3.6. In this study, we developed an Elastic Net Regression model to evaluate the factors that influence an individual's traffic violations and accidents based on an international questionnaire on traffic safety attitude, country fact survey data on traffic regulations, and other statistical databases. As a result, it was revealed that: i) In addition to country-level factors, the individual's attributes and attitudes toward traffic safety have an influence on the experience of traffic violations and accidents. and ii) While the same variables regarding individual attributes and attitudes are selected for both traffic violations and accidents, the selected variables relating to country factors differ between violations and accidents.

    DOI: 10.1016/j.iatssr.2021.12.004

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  26. Capacity Analysis of Signalized Traffic Circles in Comparison with Conventional Intersections

    BAI Yan, ZHANG Xin, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 14 ( 0 ) page: 1958 - 1975   2022.3

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    <p>Full signalized traffic circles are operating in some countries to serve the heavy turning traffic flows at large-sized road junctions. Their capacities are influenced by many factors, such as the traffic conditions, signal control types and geometric layouts. The objective of this study is to find out the specified traffic demand conditions that signalized traffic circles are preferred in different cases of the number of lanes and lane configurations. A signal optimization model for the traffic circles is proposed for investigating five cases of signalized traffic circles under various traffic demand conditions. The results showed that signalized traffic circles have higher capacity than signalized intersections in some specific cases, e.g. when the total number of approach lanes reaches five or when more than one right-turn lanes are required. Besides, an analysis on the relationship between the capacity and the occupied area is conducted to further consider the geometric influence.</p>

    DOI: 10.11175/easts.14.1958

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  27. Lane-based Evaluation of the Traffic Flow Quality of Service in Urban Expressway Weaving Segments Based on Lane Utilization Rate

    ZHOU Zhengyang, NAKAMURA Hideki, IRYO-ASANO Miho, KAKIMOTO Yuji

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 14 ( 0 ) page: 1870 - 1887   2022.3

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    <p>Weaving segments can be one of the crucial road facilities in terms of efficiency and safety on urban expressways. The traffic operation in weaving segment is different from the basic segment due to the crossing of multiple traffic streams. Also, quality of service (QOS) varies among lanes due to different lane utilization rate (LUR). Therefore, this study aims at establishing a lane-based evaluation procedure of QOS through developing LUR estimation models. With the data from two urban expressway sections in Nagoya and Tokyo, Japan, LUR is found to be significantly affected by cross-section flow, merging ratios, diverging ratios, and cross-section position. The model validation reveals that the model can reproduce traffic distribution. Lane-based average speed and density are adopted as measure of effectiveness (MOE), and level of service (LOS) criteria is determined by cluster analysis. Case study shows that the procedure can reflect QOS in each lane at every cross-section.</p>

    DOI: 10.11175/easts.14.1870

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  28. Analysis on the Relationship between Roundabout Geometric Elements and Vehicle Driving Positions

    NISHIGAKI Yuki, ZHANG Xin, KAKIMOTO Yuji, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 8 ( 2 ) page: A_15 - A_21   2022.2

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    DOI: 10.14954/jste.8.2_a_15

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  29. Modeling of Daily Speed-Flow Relationships Considering Road Condition and Traffic Flow Variations Reviewed

    KAKIMOTO Yuji, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 8 ( 2 ) page: A_62 - A_72   2022.2

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    <p>In the road project evaluation, cost-benefit analysis is conducted using the daily speed-flow relationship (Q-V), which is uniformly determined according to the road types and number of lanes. However, the existing Q-Vs cannot accurately reflect actual road traffic conditions, and they did not sufficiently take into account regional traffic conditions. In order to fill these research gaps, in this study, Q-V using traffic flow variations and the hourly speedflow relationship (q-v) considering road structure and traffic operations is modeled. The time average travel speed for each time period is calculated by using the traffic flow variations of the actual observed data and q-v. Then, by taking the weighted harmonic mean of these values, the daily average travel speed of a certain daily traffic volume was calculated and Q-V was set. The shape of the Q-V curve can be explained by the traffic flow variations, and the estimated model made it possible to estimate the Q-V considering the actual road and traffic conditions.</p>

    DOI: 10.14954/jste.8.2_a_62

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  30. Analysis of left-turn lane capacity under autonomous vehicle mixed flow considering the influence of pedestrian volume and crosswalk length

    Zhang X., Wang Y., Nakamura H., Liu K.

    Asian Transport Studies   Vol. 8   2022.1

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    Conflicts between pedestrians and left-turning vehicles cause pedestrian safety hazards and decrease vehicle turning capacity at signalized intersections. This commonly occurs in Japan where they share the same traffic light phase. Road capacity is influenced by the interaction between them. Autonomous vehicles (AVs) promise to improve the safety and efficiency of road networks. However, they will face the same problems as human-driven vehicles with pedestrian avoidance. Thus, this study estimated the capacity of the left-turn lane, in Japan, under AV mixed flows taking into account AV penetration rates, pedestrian flow rates, and crosswalk length. The impact of AVs on capacity was analyzed with different settings for the critical gap between vehicles and pedestrians. It was found that if AVs comply perfectly with traffic law, the capacity of the left-turn lane sharply decreases, especially in the case of long crosswalks.

    DOI: 10.1016/j.eastsj.2022.100070

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  31. Proposal for the Degree of Hierarchy of Road Networks using Road Use Characteristic Index

    SEKIHARA Toshihiro, KAKIMOTO Yuji, NAKAMURA Hideki, IRYO Miho, ZHANG Xin

    Proceedings of the Conference of Japan Society of Traffic Engineers   Vol. 42 ( 0 ) page: 455 - 462   2022

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    DOI: 10.14954/jsteproceeding.42.0_455

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  32. Analysis of the Relationship between the Structure of Road Networks and their Functionally Hierarchical Characteristics

    TOMINAGA Masahiro, KAKIMOTO Yuji, NAKAMURA Hideki, SEKIHARA Toshihiro

    Proceedings of the Conference of Japan Society of Traffic Engineers   Vol. 42 ( 0 ) page: 463 - 469   2022

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    DOI: 10.14954/jsteproceeding.42.0_463

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  33. ANALYSIS OF THE RELATIONSHIP BETWEEN DRIVERS' COGNITIONS AND UNSAFE DRIVING BEHAVIOR

    KAKO Yoko, KAKIMOTO Yuji, ZHU Hong, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 77 ( 5 ) page: I_915 - I_924   2022

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    <p>In recent years, the annual number of traffic fatalities in Japan has been in a decreasing trend. In order to further reduce the number of traffic accidents in the future, it is necessary to appropriately understand the relationship between the unsafe driving behaviors such as traffic violations or dangerous driving, and drivers' cognitions on them, which may directly result in traffic accidents, so that effective traffic safety policies and enforcement can be implemented. Therefore, the objective of this study is to quantitatively figure out drivers' cognitions on various unsafe driving behaviors. According to the result of the structural equation modeling based on the questionnaire survey to Japanese drivers, it was found that the younger age group the drivers belong to, the more positive attitudes they would hold for unsafe driving behavior and the more confident in their driving skills. Besides, the difference of influence by age group is particularly significant in drunk driving and careless driving, while less in overspeed driving.</p>

    DOI: 10.2208/jscejipm.77.5_i_915

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  34. Interactions between autonomous vehicles and pedestrians at unsignalized mid-block crosswalks considering occlusions by opposing vehicles

    Zhu, H; Iryo-Asano, M; Alhajyaseen, WKM; Nakamura, H; Dias, C

    ACCIDENT ANALYSIS AND PREVENTION   Vol. 163   page: 106468   2021.12

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    Visibility can be identified as one of the critical determinants for the safety performance of autonomous vehicles (AVs) on unsignalized mid-block crosswalks (UMC), which may be significantly influenced by build-up environment and surrounding vehicles. This study investigates the safety performance when AVs interact with pedestrians approaching from far-side sidewalks to UMCs considering the visual occlusion of opposing vehicles. A mathematical model is proposed for judging the visibilities of objects from observers’ location under the impact of visual obstacles and is embedded into an agent-based pedestrian-vehicle interaction framework. Two yielding decision modules is assumed for AVs: The normal decision module implements the pedestrian priority rule simply based on the current detectable information, whereas the memory aid decision module extends AVs’ detection abilities by incorporating the memory data. Through simulation experiments, it is found that the percentages of short post encroachment time (%SPET) between AVs and far-side pedestrians reach peaks when the pedestrian flow rate is 300–400 ped/h. When opposing vehicles are in stationary queue conditions, %SPETs are only sensitive to the net distance between the last opposing vehicles in the queue and crosswalks (Dqueue). As the Dqueue decreases to lower than 15 m, %SPETs start to increase drastically. However, when opposing vehicles are in free flow conditions, %SPETs are influenced by multiple factors such as pedestrians’ crossing decisions, sizes and flow rates of opposing vehicles. Furthermore, only when opposing vehicles are in free flow conditions, memory aid AVs can significantly eliminate the impacts of opposite vehicles. Finally, several countermeasures are developed to enhance the visibility and safety at UMCs based on the findings of this study.

    DOI: 10.1016/j.aap.2021.106468

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  35. A novel agent-based framework for evaluating pedestrian safety at unsignalized mid-block crosswalks

    Zhu, H; Almukdad, A; Iryo-Asano, M; Alhajyaseen, WKM; Nakamura, H; Zhang, X

    ACCIDENT ANALYSIS AND PREVENTION   Vol. 159   page: 106288   2021.9

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    A critical safety problem in road networks is the conflicts on unsignalized crosswalks. Thus, a proactive approach to assess pedestrian safety performance is required. Simulating the microscopic road user behavior in a virtual platform is one of the typical approaches. However, current simulation tools are not flexible enough to properly reproduce various behaviors of pedestrians and drivers considering their interactions with the road environment and other road users. Therefore, the objective of this paper is to propose a novel agent-based framework for evaluating pedestrian safety at unsignalized crosswalks. Unsignalized mid-block crosswalks with refuge islands (UMCR) are considered as an example facility to implement the proposed framework, where relevant behavioral elements such as the reaction time, visual field with obstacles, and minimum safety margin time are addressed. Not only the pedestrian-vehicle interaction is modeled but also the vehicle-vehicle interaction is considered. Empirical validation on a UMCR shows that the proposed framework can reproduce reliable distributions of the post encroachment time compared to the observed distributions within an acceptable error range. The sensitivity analysis reveals that the high reaction time of drivers, small safety margin time, and visual obstacles near crosswalks increase the probability of serious conflicts. The results also show that the framework can reproduce traffic crashes under assumed extreme road conditions.

    DOI: 10.1016/j.aap.2021.106288

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  36. An Analysis of the Left-turn Lane Capacity under Autonomous Vehicle Mixed Flow Considering the Influence of Pedestrian Volume and Crosswalk Length Reviewed

    Zhang, X., Wang, Y., Nakamura, H. and Liu, K.

    Proceedings for the 14th EASTS Conference     2021.9

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  37. Estimation of Roundabout Entry Capacity under Autonomous Vehicle Mixed Flows through a Traffic Simulator Reviewed

    Gao, Y., Zhang, X., Kang, N. and Nakamura, H.

    Proceedings for the 14th EASTS Conference     2021.9

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  38. Capacity Analysis of Signalized Traffic Circles in Comparison with Conventional Intersections Reviewed

    Bai, Y., Zhang, X. and Nakamura, H.

    Proceedings for the 14th EASTS Conference     2021.9

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  39. Lane-based Evaluation of the Traffic Flow Quality of Service in Urban Expressway Weaving Segments Based on Lane Utilization Rate Reviewed

    Zhou, Z., Nakamura, H., Iryo-Asano, M. and Kakimoto, Y.

    Proceedings for the 14th EASTS Conference     2021.9

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  40. Estimation Method of Left-turn Lane Capacity under the Influence of Pedestrians and Crosswalk Layout at Signalized Crosswalks Reviewed International journal

    Emagnu, M. Y., Zhang, X., Iryo-Asano, M., and Nakamura, H.

    Journal of Civil Engineering   Vol. 36 ( 1 ) page: 32 - 40   2021.6

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    DOI: 10.12962/j20861206.v36i1.9100

  41. Estimation of Expected Pedestrian Presence Time at the Conflict Area of Signalized Crosswalks Reviewed

    Emagnu, M.Y., Zhang, X., Iryo-Asano, M. and Nakamura, H.

    Journal of JSCE D3   Vol. 76 ( 5 ) page: I_1485 - I_1495   2021.4

  42. 道路ネットワークの機能階層的利用に必要な道路・交通運用条件 Reviewed

    関原敏裕・柿元祐史・中村英樹・井料美帆

    土木学会論文集D3(特集号)   Vol. 76 ( 5 ) page: I_1453 - I_1463   2021.4

  43. 道路ネットワークの機能的階層化のための道路の性能目標の設定手法に関する研究 Reviewed

    柿元祐史・中村英樹

    土木学会論文集D3(特集号)   Vol. 76 ( 5 ) page: I_1235 - I_1243   2021.4

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  44. Empirical analysis of the effect of eliminating congestion due to right turn queues by shortening the cycle length at a major signalized intersection Reviewed

    TATEMATSU Hideki, MORIMOTO Kiyoaki, TANAKA Atsushi, IZUMI Norihiro, NAKAMURA Hideki, SUZUKI Koji, IRYO Miho, KAKIMOTO Yuji

    JSTE Journal of Traffic Engineering   Vol. 7 ( 2 ) page: B_55 - B_61   2021.2

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    DOI: 10.14954/jste.7.2_b_55

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  45. A demonstration experiment of the effect of shortening the signal cycle length on a suburban minor arterial street with signalized intersections

    MAKINO Nobuhisa, KOBAYASHI Kei, IKEMIZU Takeharu, NAKAMURA Hideki, SUZUKI Koji, IRYO Miho, KAKIMOTO Yuji

    JSTE Journal of Traffic Engineering   Vol. 7 ( 2 ) page: B_6 - B_13   2021.2

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    DOI: 10.14954/jste.7.2_b_6

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  46. 信号交差点が連続する補助幹線道路における信号サイクル長短縮効果の実証実験 Reviewed

    牧野修久・小林圭・池水丈明・中村英樹・鈴木弘司・井料美帆・柿元祐史

    交通工学論文集(特集号)   Vol. 7 ( 2 ) page: B_6 - B_13   2021.2

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    DOI: 10.1080/23249935.2021.1895360

  47. A Comparative Study on the Operational Performance between Signalized Turbo Roundabouts and Signalized Intersections Reviewed

    Bai, Y., Zhang, X. and Nakamura, H.

    Asian Transport Studies   Vol. 7   2021.1

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    DOI: 10.1016/j.eastsj.2021.100033

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  48. A Comparative Study on the Capacity of Signalized Turbo Roundabouts and Signalized Intersections Considering Various Geometric Layouts Reviewed

    Bai, Y., Zhang, X. and Nakamura, H.

    100th Annual Meeting of Transportation Research Board     2021.1

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  49. Estimation of Waiting Pedestrian Occupancy-time at Signalized Crosswalks for Turning Vehicle Maneuver Analysis Invited Reviewed

    Emagnu, Y. M., Zhang, X., Iryo-asano, M. and Nakamura, H.

    100th Annual Meeting of Transportation Research Board     2021.1

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  50. Roundabout Entry Capacity Estimation under the Condition of Autonomous Vehicle Mixed Traffic Flows Reviewed

    Kang, N., Zhang, X. and Nakamura, H.

    100th Annual Meeting of Transportation Research Board     2021.1

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  51. ESTIMATION OF EXPECTED PEDESTRIAN PRESENCE-TIME AT THE CONFLICT-AREA OF SIGNALIZED CROSSWALKS

    EMAGNU Yonas M., ZHANG Xin, IRYO-ASANO Miho, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 76 ( 5 ) page: I_1485 - I_1495   2021

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    <p>Crossing pedestrians is one of the critical factors in proper estimation of turning vehicle capacities at signalized intersections. Although individual pedestrian walking speeds and consequent pedestrian platoon maneuver are influenced by traffic signal settings, crosswalk length and bidirectional interactions of pedestrian flows, the existing capacity estimation methods of left-turning vehicles did not consider these impacts. This study aims to propose a method to estimate the expected pedestrian presence-time that pedestrian platoon occupies the conflict-area, considering the characteristics of pedestrian platoon maneuvers. Referring to the existing method to estimate time-dependent pedestrian presence probability distributions, this study re-estimated the parameters of the model using the additional database with higher pedestrian demand conditions. The model revealed that the increase of opposing pedestrian flow significantly reduces spatial variation. This model was applied to calculate expected pedestri</p>

    DOI: 10.2208/jscejipm.76.5_i_1485

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  52. REQUIRED ROAD AND TRAFFIC OPERATION CONDITIONS FOR THE FUNCTIONALLY HIERARCHICAL USE OF ROAD NETWORKS

    SEKIHARA Toshihiro, KAKIMOTO Yuji, NAKAMURA Hideki, IRYO Miho

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 76 ( 5 ) page: I_1453 - I_1463   2021

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    <p>The mobility functions on arterial roads have not been fully performed due to presence of roadside access and a number of signalized intersections in Japan. In order to solve this problem, it is necessary to realize a functionally hierarchical road network that promotes the division of functions of roads according to the length of trips by differentiation of road structures and traffic operations. In this study, hypothetical road networks with three road levels were assumed, for clarifying the impact of road and traffic operation conditions on the trip characteristic indices. Then, by using an index combining the trip characteristic indices of each level of roads, requirements of road and traffic operation conditions for the road network to be used hierarchically was investigated. As a result, the requirements were identified for example, the shorter the interchange spacing is, the greater the free speed differentiation between road levels are required.</p>

    DOI: 10.2208/jscejipm.76.5_i_1453

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  53. A STUDY ON A METHOD FOR DETERMINING PERFORMANCE TARGET OF MOBILITY FUNCTION FOR FORMING A FUNCTIONALLY HIERARCHICAL ROAD NETWORK

    KAKIMOTO Yuji, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 76 ( 5 ) page: I_1235 - I_1243   2021

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    <p>Although the basic road network in Japan is almost completely constructed, a considerable portion of the roads is not functioning reasonably in terms of the expected mobility performance. The quality of service of the traffic flow is unsatisfactory, particularly on arterial highways due to access functions such as the presence of a number of signalized intersections and roadside access. In order to prevent such issues, it is necessary to clearly define the function of each road at the planning and design stage utilizing the concept of a functionally hierarchical road network. Therefore, the objective of this study is to present a method for setting performance targets necessary for each road level to form a functionally hierarchical road network, and clarify the gap between the current traffic conditions and those targets. Assuming one route using an arterial highway and another route using other local streets, the travel speed on each road type and the distance ratio of each route are evaluated. Based on this analysis, the network requirements for the arterial highway route are clarified in terms of the shortest travel time and lowest travel cost. In addition, the gaps between target travel speed and actual travel speed are analyzed using the aforementioned results as a performance target.</p>

    DOI: 10.2208/jscejipm.76.5_i_1235

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  54. The ESRA initiative: Towards global monitoring and analysis of road safety performance

    Meesmann, U; Nakamura, H

    IATSS RESEARCH   Vol. 44 ( 3 ) page: 163 - 165   2020.10

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    DOI: 10.1016/j.iatssr.2020.10.001

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  55. Modeling of a novel risk index for evaluating the geometric designs of roundabouts

    Yoshioka, K; Nakamura, H; Shimokawa, S; Morita, H

    ACCIDENT ANALYSIS AND PREVENTION   Vol. 145   page: 105702   2020.9

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    In the geometric design of roundabouts, safety-oriented approaches are required rather than specification design ones that simply determine the dimensions of the geometric structural elements. We herein propose a risk index (RI) that combines the invisibility probability and the crash impact as a performance measure for evaluating the safety of the geometric designs of roundabouts, and we also describe a method for calculating this index. Invisibility probability represents the probability that an entering vehicle cannot view a vehicle coming from the upstream in a circulatory roadway and crash impact represents the amount of lost kinetic energy at the time of collision corresponds to the impact of the crash. A numerical simulation to model this RI on the basis of various geometric conditions is further presented. It is demonstrated that the invisibility probability is large when the entry angle is small and that the crash impact increases when the deviation angle decreases. The proposed approach is expected to help resolve issues with currently existing roundabouts and improve the design of future roundabouts to enhance their safety performance.

    DOI: 10.1016/j.aap.2020.105702

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  56. Investigating the Efficiency and Safety of Signalized Intersections Under Mixed Flow Conditions of Autonomous and Human-Driven Vehicles Reviewed International coauthorship

    Pan, A., Zhang, X., Nakamura, H. and Alhajyaseen, W.K.M.

    Arabian Journal for Science and Engineering     2020.7

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    DOI: 10.1007/s13369-020-04810-1

  57. International Comparative Analysis on Car Drivers’ Awareness toward Traffic Safety

    KAKO Yoko, NAKAMURA Hideki, SUZUKI Kazufumi, KAKIMOTO Yuji

    IATSS Review   Vol. 45 ( 1 ) page: 58 - 66   2020.6

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    <p>In recent years, although the number of annual fatalities in traffic accidents in Japan is following a downward trend, the rate of decrease is shrinking. In order to reduce the number of traffic accidents more effectively, it is necessary to implement traffic safety measures based on the drivers’ awareness toward traffic safety. To understand traffic safety awareness of different countries and regions, this study conducted a questionnaire survey with drivers in Japan, Italy, and Egypt as a part of the IATSS research project. Although there was undeniably bias in the data samples, the characteristics of drivers’ awareness on traffic safety in each country were identified through comparing and analyzing their tolerance toward traffic violations and dangerous driving behaviors.</p>

    DOI: 10.24572/iatssreview.45.1_58

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  58. Introducing a multi-variate classification method: Risky driving acceptance among different heterogeneous driver sub-cultures

    Timmermans, CPM; Alhajyaseen, WKM; Ross, V; Nakamura, H

    JOURNAL OF SAFETY RESEARCH   Vol. 73   page: 81 - 91   2020.6

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    Introduction: Heterogeneous driving populations with many different origins are likely to have various sub-cultures that comprise of drivers with shared driver characteristics, most likely with dissimilar traffic safety cultures. An innovative methodology in traffic safety research is introduced which is beneficial for large datasets with multiple variables, making it useful for the multi-variate classification of drivers, driving attitudes and/or (risky) driving behaviours. Method: With the application of multidimensional scaling analysis (MDS), this study explores traffic safety culture in the State of Qatar using a questionnaire and investigates the similarity patterns between the questionnaire items, aiming to classify attitudes towards risky driving behaviours into themes. MDS is subsequently applied to classify drivers within a heterogeneous driving sample into sub-cultures with shared driver characteristics and different risky driving attitudes. Results: Results show that acceptance of speeding is highest among the young Arabic students and acceptance of distraction and drivers’ negligence such as phone use and not wearing a seatbelt is highest among male Arab drivers. Acceptance of extreme risk-taking like intoxicated driving and red-light running is highest among South-Asian business drivers. Conclusion: It is important and practical to understand risky behavioural habits among sub-cultures and thereby focussing on groups of drivers instead of individuals, because groups are easier to approach and drivers within sub-cultures are found to influence each other. By indicating which groups of drivers are most likely to perform specific risky driving themes, it is possible to target these groups and effectively emphasise certain subsets of risky driving behaviours during training or traffic safety education. Practical Applications: This study provides guidance for the improvement of driver education and targeted traffic safety awareness campaigns, intending to make changes to attitudes and habits within specific driver sub-cultures with the aim to improve traffic safety on the longer term.

    DOI: 10.1016/j.jsr.2020.02.009

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  59. Methodology to Evaluate the Quality of Service of Traffic Flow on Intercity Expressway Sections by using Follower Percentage

    Konda, H; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   Vol. 2674 ( 6 ) page: 200 - 210   2020.6

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    This study estimated composite headway distributions consisting of follower and non-follower headway elements and used the follower percentage obtained as the estimated parameters of those distributions to evaluate the quality of service (QOS) of traffic flow on Japanese intercity expressways under uncongested conditions. Analysis of pulse data obtained by vehicle detectors at multiple points with differing geometric structures showed that follower percentage is influenced by lane traffic volume, vehicle pair, and lane operation. Use of follower percentage also enabled clear and quantitative comparison and evaluation of the QOS of traffic flow for different lane operation formats, which could not be adequately expressed by such conventional macroscopic indices as average speed and traffic density. This indicates that follower percentage is a suitable performance measure for evaluating the QOS of traffic flow.

    DOI: 10.1177/0361198120918575

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  60. Modeling the Impact of Downstream Conditions on Discharging Behavior of Vehicles at Signalized Intersections Using Micro-Simulation

    Zhu, H; Nakamura, H; Alhajyaseen, W

    ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING   Vol. 45 ( 5 ) page: 4187 - 4202   2020.5

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    In areas where traffic demand is high and intersections are closely spaced, the drivers’ desire for quick discharge is demotivated by negative downstream conditions, such as long queues and poorly coordinated traffic signals, which may lead to lower saturation flow rate (SFR) for upstream lane groups. However, existing models do not consider this phenomenon. This paper proposes an improved intelligent driver model for reproducing the impacts of downstream traffic conditions on the discharging behavior of vehicles and the estimated SFR. A micro-simulation platform for two closely spaced signalized intersections is built to test the improved car-following model and to simulate the influenced SFR. Results from the sensitivity analysis and the comparison with empirical data show that the developed model could rationally and reliably reproduce the SFR reduction under different downstream conditions. As the queue in the downstream segment becomes longer and the offset becomes larger due to poor coordination, the SFR at the upstream intersection deteriorates. The developed model can be applied in traffic simulations to provide more realistic discharging behavior considering the downstream conditions.

    DOI: 10.1007/s13369-020-04411-y

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  61. Modeling Traffic Flows on Urban Arterials Considering the Downstream Influence

    Zhu, H; Nakamura, H; Alhajyaseen, W; Iryo-Asano, M

    TRANSPORTATION RESEARCH RECORD   Vol. 2674 ( 5 ) page: 475 - 485   2020.5

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    Arterials are important transportation facilities, undertaking the two functions of mobility and accessibility. In the urban area, signalized intersections along arterials are usually closely spaced and bear heavy traffic pressure. Capacities of intersections can be reduced by downstream intersections even without having spillback. This effect will be accumulated and amplified back along the traffic direction and may lead to severe congestion in the upstream intersection which can be frequently observed, especially during peak hours. However, existing traffic simulators cannot capture this phenomenon accurately because they ignore the capacity drop before spillback happens. In this study, downstream influence is quantified by a virtual optimal speed (vop). vop is the speed by which the upstream platoon reaches the endpoint of the queue ahead when the last vehicle in the downstream queue just starts. Based on that, two piecewise regression models, for start-up lost time and saturation flow rate, are formulated to estimate the capacity reduction. These regression models are further introduced to improve the modified cell transmission model (CTM). The result of the simulation experiment shows that the proposed CTM model has better performance in simulating traffic flow on signalized arterials than the existing CTM, especially in reproducing the traffic congestion in upstream. The analysis emphasized the importance of considering the downstream influence when simulating the traffic on signalized arterials. Finally, a sensitivity analysis is designed to further reveal the causes of upstream congestion.

    DOI: 10.1177/0361198120916477

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  62. Examination on Measuring Quality of Service Considering Car-Following Condition on Intercity Expressways Reviewed

    KONDA Hiroyuki, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 6 ( 2 ) page: A_9 - A_15   2020.2

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    <p>This study assumed that maneuverability such as car-following status illustrates an element related to driver perception, and investigated a performance measure capable of expressing the maneuverability as the quality of service of traffic flow (QOS). Follower percentage is such an index obtained by estimating the composite headway distribution consisting of follower and non-follower headway elements and is used as a performance measure that expresses car-following status. Analysis of pulse data obtained from vehicle detectors at multiple points on intercity expressways with different geometric structures and lane operations showed that follower percentage is influenced by lane traffic volume, vehicle pair, and lane operation. It is clarified that follower percentage can realistically express the behavioral characteristics of small and large vehicles, respectively, and probabilistically capture followers according to the actual traffic phenomenon. Thus, it can be concluded that follower percentage is a suitable index for evaluating the quality of service of traffic flow on intercity expressways under non-congested flow conditions.</p>

    DOI: 10.14954/jste.6.2_a_9

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  63. Impact of Considering Signalized Intersection Density in the Flow-Speed Formula on Benefit Estimation of Road Projects Reviewed

    KAKIMOTO Yuji, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 6 ( 2 ) page: A_198 - A_205   2020.2

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    <p>At the planning stage of road projects, their feasibility is evaluated by the cost-benefit analysis (CBA). In this process, the speed flow relationship (Q-V formula) based on the road type is being used for traffic assignment in Japan. However, in road projects such as grade separation of intersections, if the traffic volume is unchanged through the project, the estimated travel speed is also unchanged, and the effects of the project cannot be properly reflected to the CBA. In this paper, the impact of signalized intersection density on the free speed of the Q-V formula is analyzed by using a traffic simulator. An impact of benefit that is sensitive to the grade separation of intersections by using the calculated free speed is evaluated. As a result, it was confirmed that the free speed of the Q-V formula changes based on the signalized intersection density, the green time ratio and the desired speed. Finally, three benefits of road projects were calculated by a proposed Q-V formula using the free speed based on the signalized intersection density. And the effect of the new formula was clarified by showing the difference in benefits compared to the conventional method.</p>

    DOI: 10.14954/jste.6.2_a_198

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  64. A Study on using Free Speed for Estimating Expressway Quality of Service Reviewed

    AKANDWANAHO Edwin, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 6 ( 2 ) page: A_244 - A_253   2020.2

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    <p>Free speed (FS) is the speed that drivers would adopt if they were not influenced by the presence of other vehicles. This study hypothesises that the difference between the free speed distribution (FSD) and the actual speed distribution (ASD) is indicative of the quality of service (QOS) of traffic flow perceived by drivers. We use raw pulse detector data and the Modified Kaplan-Meier estimation method to derive FSD, which is then modelled based on cross-section geometry. The proposed model of FSD can be easily applied by practitioners without detailed speed and headway data. Additionally, ASD is investigated under various flow conditions, and a model is developed for its estimation based on geometric factors and traffic flow. We then define the Free Speed Index, <i>FSI = AS/FS</i> as an indicator of expressway QOS perception. <i>FSI</i> was found to decrease with an increase in traffic flow, and its potential applications are discussed.</p>

    DOI: 10.14954/jste.6.2_a_244

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  65. 追従車構成率を用いた都市間高速道路の交通流のサービスの質の評価 Reviewed

    近田博之・中村英樹

    高速道路と自動車   Vol. 63 ( 2 ) page: 22 - 29   2020.2

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  66. Analysis of Travel Speed on 4-Lane Signalized Arterials

    Akandwanaho E., Nakamura H.

    Transportation Research Procedia   Vol. 48   page: 890 - 903   2020

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    Signalized intersections are the major causes of delay to vehicular traffic along signalized arterials. Although a lot of research has been conducted about the optimization of the performance of signalized intersections, it is mostly applicable to the operations stage and involves changing signal phasing schemes. However, due to cost of roadways construction and the additional improvements after construction, the assessment of the potential performance of the roadway is very important even at the planning stage so that the plans do not call for some unfavorable design features along the arterial. The lack of performance oriented planning often leads to poor performance, such as very low travel speeds. In this work, we investigate the travel speed along a hypothesized 4-lane signalized arterial, and examine how it changes due to the signalized intersection density, cycle length, mean desired speed, and the function of the intersection. Results showed that cycle lengths up to 120 seconds were sufficient to yield high travel speed. At higher intersection densities, lower travel speeds will be achieved regardless of the mean desired speed. The function of the signalized intersection was also significant, showing the possibility of maintaining the traffic function of an arterial if it were crossed by a lower level road in the hierarchy. The importance of performance evaluation at the planning stage was further emphasized.

    DOI: 10.1016/j.trpro.2020.08.106

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  67. Traffic safety culture of professional drivers in the State of Qatar

    Timmermans, C; Alhajyaseen, W; Reinolsmann, N; Nakamura, H; Suzuki, K

    IATSS RESEARCH   Vol. 43 ( 4 ) page: 286 - 296   2019.12

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    Professional drivers play a significant role within the traffic system of the State of Qatar. With developing infrastructure, the need for professional drivers is growing. However, knowledge is lacking about their perception of traffic safety. Therefore, this study investigates the personal acceptance of risky driving and suggested traffic laws among this specific group of drivers, in order to create understanding about their likelihood to commit certain risky driving behaviors and their resistance to the implementation of certain traffic laws. The aim of this study is to establish which personal attributes of professional drivers in Qatar could influence a high likelihood to commit risky driving behaviors, estimating which specific groups of professional drivers impose the highest risk to violate certain traffic laws. Results indicate that transportation mode, origin and years of driving experience are all personal attributes that have a significant impact on the professional driver's risk to commit risky driving behaviors and their opposition to the implementation of related traffic laws. Distressing results have been found for the high likelihood to violate speed in school zones and the high risk to be distracted by any type of phone use while driving, suggesting the need to put emphasize on these safety hazards during the training programs of professional drivers at professional driving schools in the State of Qatar.

    DOI: 10.1016/j.iatssr.2019.03.004

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  68. Study on Start-up Lost Time at Signalized Intersections Considering Downstream Conditions Reviewed

    Zhu, H. and Nakamura, H.

      Vol. 75 ( 5 ) page: I_1121 - I_1130   2019.12

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  69. Estimation of Roundabout Entry Capacity and Passenger Car Equivalent for Heavy Vehicles Considering the Impact of Geometric Elements Reviewed

    Fang, Y., Zhang, X. and Nakamura, H.

    Journal of JSCE D3   Vol. 75 ( 5 ) page: I_1167 - I_1176   2019.12

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  70. ラウンドアバウト幾何構造の安全性能評価のためのリスク指標モデリング Reviewed

    吉岡慶祐・中村英樹・下川澄雄・森田綽之

    土木学会論文集D3   Vol. 75 ( 3 ) page: 191 - 201   2019.10

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  71. An Analysis on the Impact of Autonomous Vehicle Mixture on Capacity of Signalized Intersections

    WANIBE Kazuma, KAKIMOTO Yuji, NAKAMURA Hideki, IRYO-ASANO Miho

    JSTE Journal of Traffic Engineering   Vol. 5 ( 2 ) page: A_167 - A175   2019.2

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    <p>In recent years, driving support systems have begun to be installed in the real field, and expectations for improvement in safety and efficiency by autonomous vehicles are increasing. However, these expectations are not necessarily realized at the stage of popularization of autonomous vehicles. Particularly, at signalized intersections, because vehicles interact with each other in a complicated manner, efficiency may be affected depending on the setting of the behavior parameters of autonomous vehicles. Thus, this paper analyzes the influence of setting of parameters of autonomous vehicles on capacity of through lanes at signalized intersections by using simulation and model equation, and the capacity is calculated by using simulation result considering parameter settings and mixture ratio. As a result, while it became clear that the cycle length can be shortened by spreading of autonomous vehicles, it is suggested that by inputting discreet setting of the parameters of autonomous vehicles, the efficiency may decrease.</p>

    DOI: 10.14954/jste.5.2_a_167

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  72. Introduction

    Tang K.

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections     page: 1 - 5   2019.1

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    Publishing type:Research paper (scientific journal)   Publisher:Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  

    DOI: 10.1016/B978-0-12-815302-4.00001-7

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  73. ESTIMATION OF ROUNDABOUT ENTRY CAPACITY AND PASSENGER CAR EQUIVALENT FOR HEAVY VEHICLES CONSIDERING THE IMPACT OF GEOMETRIC ELEMENTS

    FANG Yao, ZHANG Xin, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 75 ( 5 ) page: I_1167 - I_1176   2019

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    <p>Entry capacity is one of the most important indexes to evaluate the roundabout operational performance. Both the geometric elements and vehicle types have an impact on the entry capacity. Passenger Car Equivalent (PCE) for heavy vehicles is utilized for roundabout entry capacity estimation. In the Japanese Roundabout Manual (JRM), PCE is proposed as a constant value. However, it cannot reflect that the capacity of roundabouts varies with different geometric elements and heavy vehicle percentages. Therefore, the objective of this study is to estimate the PCE for heavy vehicles depending on various geometric elements. Entry capacity and PCE were estimated by the entry capacity equation in JRM and traffic simulator VISSIM, respectively. The results revealed that the entry capacity changes with different geometric elements and is significantly related to inscribed circle diameter. It was also concluded that PCE changes with increasing heavy vehicle percentages in the entering and circulating flows.</p>

    DOI: 10.2208/jscejipm.75.i_1167

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  74. MODELING A RISK INDEX FOR EVALUATING THE SAFETY PERFORMANCE OF ROUNDABOUT GEOMETRIC DESIGN

    YOSHIOKA Keisuke, NAKAMURA Hideki, SHIMOKAWA Sumio, MORITA Hirohisa

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 75 ( 3 ) page: 191 - 201   2019

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    <p> For the geometric design of a roundabout, a safety-oriented approach is required rather than a simple specification dependent design that normatively determines dimensions of the geometric elements. However, such a safety performance index or evaluation methodology has yet to be included in the Japanese guidelines. In this study, we propose a risk index (RI) that combines the mislook probability and crash impact as a performance index for evaluating the safety of roundabout geometric designs; a method to calculate this index is also described. Then, a model equation to calculate the RI from the geometric conditions throughout the numerical simulation is presented. Finally, it is demonstrated that the mislook probability is greater when the entry angle is lower, and the crash impact increases when the deviation angle decreases.</p>

    DOI: 10.2208/jscejipm.75.191

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  75. STUDY ON START-UP LOST TIME AT SIGNALIZED INTERSECTIONS CONSIDERING DOWNSTREAM CONDITIONS

    ZHU Hong, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 75 ( 5 ) page: I_1121 - I_1130   2019

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    <p>Start-up lost time (SLT, hereinafter) is one of the basic parameters for evaluating the capacities of signalized intersections. In the urban area, intersections are closely spaced and traffic demand is high. Drivers’ ambitions for the quick startup are demotivated by negative downstream traffic conditions, for example, limited available storage length, long queue and/or poorly coordinated traffic signals. The performance of upstream intersection is deteriorated including the growth in the SLT. In this paper, the influence of downstream conditions over SLT is analyzed by empirical study. The result indicates that SLTs at subject intersections are mainly influenced by downstream queue length, offset, segment length, and clearing vehicles. Short downstream segment length, long queue, positive offset, and long clearing time will lead to a high SLT value. Regarding this finding, the effect is further investigated by developing a new car-following model. The new model is built by improving the intelligent driver model and calibrated it with empirical data by a genetic algorithm. Through scenario simulation and comparison with empirical data, it is proved that the new model not only can reproduce the SLT increase under different downstream conditions but also have a good fit with real-world data.</p>

    DOI: 10.2208/jscejipm.75.i_1121

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  76. A comparative study on the operational performance of four-leg intersections by control type

    Arshi Abubeker N., Alhajyaseen Wael K. M., Nakamura Hideki, Zhang Xin

    TRANSPORTATION RESEARCH PART A-POLICY AND PRACTICE   Vol. 118   page: 52 - 67   2018.12

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    DOI: 10.1016/j.tra.2018.08.039

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  77. Performance evaluation of the inside intersection median-turn lane markings on the mobility and safety performance of signalized intersections in the Philippines and Japan

    Jowhell Villegas John, Alhajyaseen Wael K. M., Nakamura Hideki, Goto Azusa

    IATSS RESEARCH   Vol. 42 ( 4 ) page: 230 - 239   2018.12

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    DOI: 10.1016/j.iatssr.2017.12.001

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  78. Editors' notes: Special issue on innovative intersection design and control for serving multimodal transport users

    Tian Zong, Nakamura Hideki, Boltze Manfred, Chung Edward

    TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES   Vol. 86   page: 639 - 640   2018.1

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    DOI: 10.1016/j.trc.2017.11.022

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  79. A Study on the Impact of AV-HDV Mixed Traffic on Flow Dynamics of Single-Lane Motorway

    Kakimoto Yuji, Iryo-Asano Miho, Orhan Emre, Nakamura Hideki

    INTERNATIONAL SYMPOSIUM OF TRANSPORT SIMULATION (ISTS'18) AND THE INTERNATIONAL WORKSHOP ON TRAFFIC DATA COLLECTION AND ITS STANDARDIZATION (IWTDCS'18) - EMERGING TRANSPORT TECHNOLOGIES FOR NEXT GENERATION MOBILITY   Vol. 34   page: 219 - 226   2018

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    DOI: 10.1016/j.trpro.2018.11.035

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  80. A Study on the Average Travel Speed on Interrupted Flow Multi-Lane Highways

    Akandwanaho Edwin, Iryo Miho, Nakamura Hideki

    INTERNATIONAL SYMPOSIUM OF TRANSPORT SIMULATION (ISTS'18) AND THE INTERNATIONAL WORKSHOP ON TRAFFIC DATA COLLECTION AND ITS STANDARDIZATION (IWTDCS'18) - EMERGING TRANSPORT TECHNOLOGIES FOR NEXT GENERATION MOBILITY   Vol. 34   page: 51 - 58   2018

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    DOI: 10.1016/j.trpro.2018.11.013

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  81. A Lane-Based Analysis of Stochastic Breakdown Phenomena on an Urban Expressway Section

    GOTO Azusa, KATO Daichi, NAKAMURA Hideki

    Asian Transport Studies   Vol. 5 ( 1 ) page: 64 - 80   2018

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    In this study, stochastic breakdown phenomena on a two-lane section of a Japanese urban expressway are analyzed and modeled. Because the bottleneck of the subject section is supposed to be a complex geometry with an on-ramp, a horizontal curve and an uphill, analysis is conducted not only by cross section but also by lane to understand the characteristics of breakdowns in detail. For such a detailed analysis, applicability and limitation of the detector data with different aggregation intervals are also considered. Through the analysis, it is found that about 40% of breakdowns in the section occur first on the shoulder lane; one of the causes would be higher merging traffic volume. The estimation of breakdown probability shows that the capacity of the median lane is about 300-veh/h greater than that of the shoulder lane. Furthermore, it is found that the discharge flow rate deteriorates as the elapsed time after breakdown increases, especially at the beginning of congestion.

    DOI: 10.11175/eastsats.5.64

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  82. An Analysis on Impact of Roundabout Geometric Elements on Driving Behavior Reviewed

    YOSHIOKA Keisuke, NAKAMURA Hideki, SHIMOKAWA Sumio, MORITA Hirohisa

    JSTE Journal of Traffic Engineering   Vol. 4 ( 1 ) page: A_47 - A_54   2018

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    <p>For the safety performance and smooth operation of roundabouts, designing geometric elements that can realize appropriate driving behavior is an important issue, particularly regarding the S-shaped trajectory which is different from ordinary cross intersections. However in Japan, this kind of driving behavior characteristics on roundabouts has not yet been studied enough. In this study, video surveys for driving behavior by using an UAV were carried out at seven roundabouts with different geometric design and the impact of geometric design elements on driving behavior are analyzed. As a result, the entry corner radius and the turning angle which is formed by entry and exit legs are shown as critical factors for the lateral acceleration applied to the vehicle. Moreover, it is shown that oversized entry corner radius and turning angle smaller than 150 degrees could lead to lower lateral acceleration and result in lower speed control effect on straight through vehicles.</p>

    DOI: 10.14954/jste.4.1_a_47

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  83. APPLICABILITY OF SAFETY PERFORMANCE EVALUATION METHOD FOR ROUNDABOUTS TO JAPAN

    YOSHIOKA Keisuke, NAKAMURA Hideki, SHIMOKAWA Sumio, MORITA Hirohisa

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 74 ( 5 ) page: I_1037 - I_1046   2018

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    Since the revision of the Road Traffic Law in 2014, roundabouts have been implemented and planned throughout Japan, and further spread is expected in the future. The geometric design of roundabout is a process of determining combinations of various geometric elements, and it is indispensable to evaluate safety performance for the entire geometry in this process. However, in Japan, concrete methods and indicators for evaluating safety performance have not been considered. Therefore, in this research, overseas design guidelines have reviewed the policies or features of performance evaluation based on “Fastest Path” and “Deflection Angle”. Furthermore, the geometric design of existing roundabouts was evaluated and the applicability to Japan was discussed.

    DOI: 10.2208/jscejipm.74.i_1037

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  84. A ROUNDABOUT ENTRY CAPACITY ESTIMATION MODEL CONSIDERING THE IMPACT OF GEOMETRIC ELEMENTS

    KANBE Nobuto, ZHANG Xin, NAKAMURA Hideki, ODAKA Shinji

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 74 ( 5 ) page: I_1399 - I_1409   2018

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    Entry capacity of roundabouts should be confirmed when considering their introduction. However, since there are still few roundabouts in Japan, the impact of roundabout geometry on entry capacity is still unclear. In addition, although the roundabout entry capacity in Japan is calculated based on the gap acceptance theory, the impact of roundabout geometry on the necessary gap parameters has not been clarified. Therefore, in this study the impact of roundabout geometry on entry capacity of roundabouts was analyzed using empirical data from Japan, and an estimation model of the gap parameters using geometry and traffic conditions as explanatory variables was proposed. Based on this, the influence of roundabout geometry on entry capacity was quantitatively clarified.

    DOI: 10.2208/jscejipm.74.i_1399

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  85. Evaluation of the Unsignalized Two-stage Crossing on Basic Road Sections

    ISHIYAMA Ryota, GOTO Azusa, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 4 ( 1 ) page: A_8 - A_16   2018

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    <p>In Japan's unsignalized crosswalks on basic road sections, it is hard to say that safety and efficiency of crossing pedestrians are sufficiently ensured. On the other hand, in recent years, attention has been paid to a "two-stage crossing", that is a method in which a crosswalk is split into two stages by using a median island. However, as application examples are still limited in Japan, it is necessary to quantitatively show its effect. In this study, stop-or-go decisions of pedestrians at crosswalks were analyzed considering the impacts of pedestrian crossing time as well as position and speed of approaching vehicles by using observed data. Based on that, the change of the critical gap at the time of applying the two-stage crossing was estimated by formulating a pedestrian gap acceptance model. In addition, the effect of improving efficiency was quantitatively evaluated, by calculating the average delay of crossing pedestrians using this critical gap.</p>

    DOI: 10.14954/jste.4.1_a_8

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  86. A STUDY ON STOCHASTIC BREAKDOWN PHENOMENA IN INTERCITY EXPRESSWAY LANE DROP SECTIONS

    KATO Daichi, KAKIMOTO Yuji, NAKAMURA Hideki, GOTO Azusa

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 74 ( 5 ) page: I_1411 - I_1418   2018

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    Recently, a lot of knowledge has been accumulated about breakdown phenomena on expressways, their occurrence mechanisms, stochastic nature, and the differences in the pre- and post-breakdown capacities. However, in sections where lane use characteristics have a large effect – such as in lane drop sections, although capacity reduction is known to occur, there are still many unclear points, and more detailed analysis is necessary. Therefore, in this paper, we analyzed the mechanism before and after breakdown in several sections with different usage of the narrowing lane. Breakdown probability curves were estimated based on lane use characteristics, and it was found that the breakdown probability was highest in merging lanes, followed by passing lanes, and was lowest in lane one. This is because in lane one there is little variation in lane usage before breakdown, and left-side overtaking occurs in the merging lane, showing that the influence of lane use characteristics is large.

    DOI: 10.2208/jscejipm.74.i_1411

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  87. Assessing Safety of Signalized Intersections Influence of Geometric Attributes and Regionality on Traffic Accident Risk

    Shiomi Yasuhiro, Watanabe Kazuki, Nakamura Hideki, Akahane Hirokazu

    TRANSPORTATION RESEARCH RECORD   Vol. 2659 ( 2659 ) page: 71 - 79   2017.1

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    DOI: 10.3141/2659-08

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  88. An Analysis of Characteristics of Heavy Vehicle Behavior at Roundabouts in Japan

    Kang Nan, Nakamura Hideki

    WORLD CONFERENCE ON TRANSPORT RESEARCH - WCTR 2016   Vol. 25   page: 1485 - 1493   2017

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    DOI: 10.1016/j.trpro.2017.05.176

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  89. A study on appropriate road spacing for the functionally hierarchical network planning

    Goto Azusa, Nakamura Hideki

    WORLD CONFERENCE ON TRANSPORT RESEARCH - WCTR 2016   Vol. 25   page: 3821 - 3829   2017

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

    DOI: 10.1016/j.trpro.2017.05.266

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  90. Modelling Travel Speed along Japanese Highways/Streets for Planning Stage Application

    AKANDWANAHO Edwin, GOTO Azusa, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 12 ( 0 ) page: 1604 - 1618   2017

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    Accurate estimation of travel speed along a transport facility is necessary in order to ensure that the facilities meet the required performance. In this paper, the performance of the Highway Capacity Manual travel speed model is checked for Japanese roads. Then, a travel speed estimation model is developed from data collected along a road section in Hamamatsu City, Japan. The model provides an estimate of the average travel speed along a road section by inputting demand flow rates, section length, number of signalised intersections, signalised intersection density, and the number of access points along the road in the travel direction. It is found that the travel speed slightly increases with increased section length, and decreases with increased access points and higher number and density of signalised intersections.

    DOI: 10.11175/easts.12.1604

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  91. Analytical Study on the Relationship between Level of Pedestrian-vehicle Separation and Performance of Signalized Intersections

    ZHANG Xin, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 3 ( 5 ) page: 11 - 20   2017

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    One of the measures to inhibit conflicts between pedestrian and left-turning vehicle at crosswalk of signalized intersections is, to provide separate phases for pedestrian and turning vehicle, such as exclusive pedestrian phase or Leading Pedestrian Interval (LPI). LPI is the phase which pedestrian green is displayed a few seconds ahead of vehicle green phase, and in this preceding time interval, a part of pedestrians can be protected from the conflicting left-turning vehicles. From the viewpoint of safety and mobility performance, LPI can be positioned between the conventional four-phase type in which the concurrent pedestrians and vehicles share the same signal phase and the exclusive pedestrian phase type. However, the safety and mobility performance of these three types of signal phasing is unclear. Thus, this study investigates and compares delays of pedestrian and vehicle, degree of saturation, capacity and pedestrian exposure time under those three types of signal phase types. Then an application range of LPI and the boundary condition of exclusive pedestrian phase are discussed.

    DOI: 10.14954/jste.3.5_11

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  92. A STUDY ON ESTIMATION PROCEDURE OF CRITICAL GAPS AT ROUNDABOUTS

    GOTO Azusa, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 73 ( 5 ) page: I_1243 - I_1250   2017

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    Critical gap is an important parameter for not only entry capacity estimation but also safety evaluation at roundabouts. This paper gives an overview on the existing procedures for estimating critical gaps and compares them by applying into an empirical data observed at a roundabout in Japan. Application of other procedures than Raff's method, which has been commonly used in Japan, enables to estimate not only a single representative value of critical gaps (e.g., mean or median) but also their distribution. Through a comparison, differences of the estimated critical gap distributions are presented and discussed considering the limitation in the observed samples.

    DOI: 10.2208/jscejipm.73.i_1243

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  93. ラウンドアバウト幾何構造設計の安全性評価指標に関する検討

    中村 英樹

    土木計画学研究・講演集   Vol. 55   2017

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  94. 幾何構造要因を考慮したラウンドアバウト流入交通容量のモデル化

    中村 英樹

    土木計画学研究・講演集   Vol. 55   2017

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  95. Impact of Inside Intersection Pavement Markings to Mobility Performance at Urban Signalized Intersections in Japan and the Philippines

    VILLEGAS John Jowhell, GOTO Azusa, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 12 ( 0 ) page: 1637 - 1650   2017

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    Inside intersection pavement markings category in Japan and Philippines are different, and the difference of its impact to mobility performance are still unknown. Left-turn lanes (right-turn in Japan) is one of key movements in urban signalized intersections and their capacity must be maximized. This paper aims to investigate the difference of the mobility performance of the right-turn guide lines in Japan and Yellow-Box pavement markings in the Philippines in terms of saturation flow rate, trajectory variation and speed. The analysis reveals that the turn guide lines are effective in achieving small turning vehicle trajectory variation and high saturation flow rate which are affected by the traffic signal phasing and the geometric layout of the turn lanes of the signalized intersection. The absence of guide lines of yellow box pavement markings creates cross-maneuvering behavior that lower the saturation flow rate of the turning lane.

    DOI: 10.11175/easts.12.1637

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  96. A Factor Analysis of Traffic Accident Frequency by Type on Major Road Sections in Japan

    WATANABE Kazuki, NAKAMURA Hideki

    Asian Transport Studies   Vol. 4 ( 2 ) page: 392 - 407   2016

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    This study aims to identify influencing factors of traffic accidents on Japanese major roads through factor analysis and regression analysis for each accident type, considering their characteristics as rare events. The database consists of a five-year accident record and relevant road traffic condition data on major road sections in Aichi Prefecture, which includes the third largest conurbation area of Japan. From the results of the factor analysis, a trend of high accident rates in broad urban arterials is confirmed, and rear-end or side collisions are widely distributed in suburban areas. From the regression analysis, results reveal that the degree of impact by traffic volume is dependent on accident type, and suggests that several factors related to visibility have an influence on turning and side collisions. The study suggests that improving the quality of traffic flow on major roads by ensuring proper intersection spacing is important for establishing a safer road network.

    DOI: 10.11175/eastsats.4.392

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  97. Development and Validation of a Roundabout Entry Capacity Model Considering Pedestrians under Japanese Conditions

    KANG Nan, KANBE Nobuto, NAKAMURA Hideki, ODAKA Shinji

    Asian Transport Studies   Vol. 4 ( 2 ) page: 350 - 365   2016

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    Besides circulating flow, pedestrian flow is another key conflict stream that significantly influences roundabout entry capacity. Due to limited space in Japan, several standard designs such as a physical splitter island cannot always be installed at the roundabout entry/exit. The impact of several influencing factors on entry capacity such as splitter islands was examined by applying a microscopic simulation to our previous research. A regression model was proposed based on the simulation results, which assumed that vehicles yielded to all pedestrians at the beginning of the crosswalk. In this paper, the regression model was validated using field data observed in Japan. The regression model was improved by adding a parameter to reflect drivers’ compliance with pedestrians. The validation results indicate that the improved model shows good fitness to the field data and the results imply that roundabout geometry and traffic flow composition significantly influence entry capacity.

    DOI: 10.11175/eastsats.4.350

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  98. A STUDY ON COMPOSITION OF FUNCTIONALLY HIERARCHICAL ROAD NETWORK WHICH CONSIDERS TRAVEL PERFORMANCE BETWEEN CENTERS

    GOTO Azusa, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 72 ( 5 ) page: I_939 - I_954   2016

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    In Japan, reorganization of road network into functionally hierarchical form becomes more important so as to efficiently improve travel performance between centers where daily-life and/or urban services are provided. This study aims at investigating the appropriate composition of a functionally hierarchical road network which can achieve the target travel times set for various connections of centers in the subjective region. Here, composition is defined as a combination of the number of hierarchical road levels, target travel speed, road spacing and access spacing of each road level. In this paper, alternatives of such a composition are derived by considering the impact of road crossings as well as roadside access. At the end, a case study is conducted in Tokaido region, Japan, and travel performance indices, namely travel time and average travel speed, between various types of centers are estimated under each alternative composition of a functionally hierarchical road network. The result shows that road level with higher travel speed (i.e., 50~60km/h) can significantly work especially for the communities in peninsula and mountainous rural area by enhancing the accessibility to urban centers.

    DOI: 10.2208/jscejipm.72.i_939

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  99. Gap acceptance analysis of right-turn vehicles considering positions of opposing through vehicles

    WATANABE Kazuki, Nakamura Hideki

    JSTE Journal of Traffic Engineering   Vol. 2 ( 2 ) page: A_85 - A_91   2016

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    The gap acceptance behavior to the opposing through traffic of “permitted” right-turn vehicles is one of the important events for evaluating the safety of signalized intersections. In this study, a decision-making process of gap acceptance was carefully investigated through paying attention to a difference by the number of opposing approach lanes. Moreover, a gap acceptance model of permitted right-turn vehicles at the multilane signalized intersection was developed considering arriving vehicles’ positions in the multiple opposing approach lanes by using binomial logit model. The model estimation result quantitatively showed that the gap acceptance decision is being influenced not only by gap times and arrival through vehicle speeds but also by their driving positions at the intersection approach lane. Furthermore, the calculation result of the critical gap time suggested that it varies depending on the positions of opposing through vehicles in the multilane intersection comparing to the case of single opposing lane intersection.

    DOI: 10.14954/jste.2.2_a_85

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  100. Modeling pedestrian density distribution on crosswalk of signalized intersections and its application for setting Leading Pedestrian Interval (LPI)

    ZHANG Xin, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 2 ( 2 ) page: A_183 - A_192   2016

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    Timing of pedestrian phase plays an important role in the safety and mobility performance at signalized intersections. In order to evaluate the performance, it is useful to understand effects of crosswalk length and signal timing on pedestrian presence position and timing. This study investigates the effects of elapsed pedestrian green time, waiting time, crosswalk length and pedestrian volume on the spatiotemporal probability of pedestrian presence and models its distributions considering these influencing factors. It was found that pedestrian presence probability distributions shift to the moving direction as pedestrians proceed. The shorter pedestrian waiting time and longer crosswalk length lead to the wider distribution of pedestrian presence probability. In addition, application of the pedestrian presence probability model for setting Leading Pedestrian Interval (LPI) is discussed. Possible ranges of LPI are investigated dependent on crosswalk length, vehicle flow rate and ratio of pedestrian having passed the conflict area according to pedestrian directional rate.

    DOI: 10.14954/jste.2.2_a_183

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  101. QUANTITATIVE ANALYSIS ON RISK FACTORS FOR ROAD TRAFFIC ACCIDENTS CONSIDERING GEOMETRIC FEATURES OF INTERSECTIONS

    SHIOMI Yasuhiro, WATANABE Kazuki, NAKAMURA Hideki, AKAHANE Hirokazu

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 72 ( 4 ) page: 368 - 379   2016

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     More than half of traffic accidents on arterial road networks occur at intersections. To enhance traffic safety, it is essential to identify the risk factors with qualitative manner, and to reform the configuration of intersections and improve the traffic management for removing the risk factors. In this study, first we collected the data of intersection geometric attributes and lane configurations by using virtual database (cf. Google Earth and Google Street View), which was integrated with the data of traffic accidents, road networks, and traffic volume. Then, Poisson regression models were applied to statistically identify the risk factors on categorized traffic accidents. Finally, the expected number of reduction of traffic accidents are estimated based on the regression models when the reformations are applied to the intersections in Kagawa. As a result, those findings are obtained; (i) the geometric attributes of intersections are significantly varied among prefectures (Kagawa, Shiga, and Aichi), which can be considered as regional characteristics; (ii) as the size of intersections becomes large, the risk of traffic accidents becomes worse, which implies that downsizing of intersection may contribute to improve the traffic safety; (iii) according to the proposed reforming scenario for intersections in Kagawa, there is a potential that the total number of traffic accidents could be reduced by more than 35%.

    DOI: 10.2208/jscejipm.72.368

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  102. Passenger Car Equivalent of Heavy Vehicles for Roundabout Entry Capacity Estimation Reviewed

    GOTO Azusa, KANG Nan, NAKAMURA Hideki, MASHIMA Kiminori

    JSTE Journal of Traffic Engineering   Vol. 2 ( 6 ) page: 11 - 19   2016

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    As implementation of roundabouts is being discussed at more numbers of places after the partial revision of Road Traffic Law in 2014, quantifying the impact of heavy vehicles on entry capacity is an important and urgent task in Japan. The objective of this study is to estimate passenger car equivalent (PCE) of heavy vehicles at roundabouts in Japan. Since the number of actual roundabouts is still limited, this study adopts a microscopic traffic simulator for obtaining entry capacity under various heavy vehicle percentages in either entry or circulating flow. Then, passenger car equivalents at entry and circulatory roadway are derived based on the simulated capacities. As a result, it is found that the estimated passenger car equivalent is higher at entry than at circulatory roadway. At the end, entry capacity with heavy vehicles in both entry and circulating flows simultaneously is reasonably calculated by using the estimated passenger car equivalents.

    DOI: 10.14954/jste.2.6_11

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  103. 交差点の安全対策としてのラウンドアバウト

    中村 英樹

    自動車技術   Vol. 70-3   page: 74 - 78   2016

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  104. Analysis and Modeling of Pedestrian Crossing Behavior During the Pedestrian Flashing Green Interval

    Iryo-Asano, M; Alhajyaseen, WKM; Nakamura, H

    IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS   Vol. 16 ( 2 ) page: 958 - 969   2015.4

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    Pedestrian-vehicle conflicts are considered one of the most common safety problems at signalized intersections. In Japan, the pedestrian flashing green (PFG) is considered a safe time interval for pedestrians at crosswalks to finish crossing before conflicting vehicle streams are released. In most common phasing schemes, pedestrians have the right-of-way along with left-turning vehicles (in left-hand traffic). By law, pedestrians should not enter a crosswalk during the PFG. However, many of them rush into crosswalks without necessarily heeding approaching turning vehicles, which could increase the probability of severe conflicts. The objective of this paper is to analyze and model the probabilistic behavior of pedestrians after the onset of the PFG, which contains the pedestrians' decision of whether to give up crossing, as well as the pedestrian speed distribution. Empirical data analysis showed that longer crosswalks lead to significantly higher pedestrian stop probabilities. Furthermore, there is a significant difference between the pedestrians' speeds in the first and second halves of crosswalks. The results of a Monte Carlo simulation showed that the estimated models closely represent the overall stochastic behavior of the pedestrians from the onset of the PFG until the completion of crossing.

    DOI: 10.1109/TITS.2014.2346154

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  105. Esimation of Roundabout Entry Capacity That Considers Conflict with Pedestrians

    Kang, N; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   Vol. 2517 ( 2517 ) page: 61 - 70   2015

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    At roundabouts, the main streams that conflict with entry flow and have a significant effect on entry capacity are circulating flow and pedestrian flow. Pedestrian impact is estimated with an adjustment factor ( fped) in existing methods that were developed under standard roundabout designs, such as a physical splitter island at entry and exit. However, available space may limit these geometric designs in some locations (e.g., in Japan), and, as a result, the impact of driver and pedestrian behaviors on entry capacity probably changes. In a microscopic approach, entry vehicles cross pedestrian flow through available pedestrian gaps. Therefore, gap acceptance behavior is used to reproduce conflict with pedestrians. This analysis aimed to estimate roundabout entry capacity that considers conflict with pedestrians by gap acceptance behavior as well as several influencing factors, including presence or absence of a physical splitter island and the farside pedestrian yield rate (i.e., number of drivers yielding to the total farside pedestrian demand). Entry capacity was estimated two ways, with simulation analysis and a theoretical model. The estimated entry capacity results from the two approaches were compared, and the limitations of each approach were interpreted. Results from the two proposed approaches also were compared with those from the existing fped model that was applied in Highway Capacity Manual 2010 (referred to as HCM fped). Findings imply that HCM fped is not appropriate for Japanese situations. Both proposed approaches are expected to be used in the planning and design stages for roundabout implementation not only in Japan but also in other countries that must consider space limitations and pedestrians.

    DOI: 10.3141/2517-07

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  106. Modeling Pedestrian Presence Probability on Signalized Crosswalks for the Safety Assessment Considering Crosswalk Length and Signal Timing

    ZHANG Xin, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 11 ( 0 ) page: 1403 - 1415   2015

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    Quantifying effects of crosswalk length and signal timing on pedestrians' presence position and timing is an important requirement for evaluating the probability of conflict. It can be utilized to provide a rational safety assessment and improve existing operational policies at signalized intersections. This study investigates the effects of crosswalk length and pedestrian green time on the spatiotemporal probability of pedestrian presence. It was found that the longer pedestrian green time and crosswalk length leads to the wider distribution of pedestrian presence probability. In addition, a surrogate safety measure for assessing pedestrian safety is proposed by utilizing the pedestrian presence probability model.

    DOI: 10.11175/easts.11.1403

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  107. Setting the Target Performance for Functionally Hierarchical Road Network Planning

    GOTO Azusa, NAKAMURA Hideki

    JSTE Journal of Traffic Engineering   Vol. 1 ( 2 ) page: A_107 - A_115   2015

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    For functionally hierarchical road planning, it is important to set the appropriate target network defined by the number of road levels, road spacing and target travel speed of each road level, considering distribution of urban city centers, target travel time among them and demand characteristics. This study proposes a methodology to determine the variables that define target network based on the percentage of urban centers between which their target travel time is achieved as well as construction cost. In this methodology, target travel speed ratio is assumed to be proportional to road spacing ratio between two connected road levels, and the road levels with the highest or lowest target travel speed needs to be given in advance. These assumptions enable to limit the number of scenarios with realistic combinations of road spacing and target travel speed under the trade-off between mobility and access functions. Finally, a simple case study is conducted with a hypothetical grid network assuming some typical urban center distribution. As a result, the effects of number of road levels and target travel speeds on travel time by trip length and construction cost are demonstrated.

    DOI: 10.14954/jste.1.2_a_107

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  108. A Study on Roundabout Entry Capacity Model Considering Pedestrians under Japanese Conditions Reviewed

    KANG Nan, NAKAMURA Hideki, KANBE Nobuto

    JSTE Journal of Traffic Engineering   Vol. 1 ( 5 ) page: 19 - 28   2015

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    The existing methodology for roundabout entry capacity estimation is assuming the standard geometric layout and user behavior in other countries. However in Japan, it is often likely that the physical splitter islands are not implemented mainly due to space limitations, and thus pedestrian behavior and its impacts on entry capacity are different from those in the other countries. In this paper, simulation analyses were carried out with respect to impacts of geometry and user behavior conditions that are typical in Japan on entry capacity, and by using their results a multiple regression model for entry capacity estimation was developed. The model was validated with data observed at Roppontsuji roundabout in Karuizawa, Nagano. It was found that the estimation performance of the proposed model was very satisfactory while the existing methodology overestimates the capacity.

    DOI: 10.14954/jste.1.5_19

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  109. AN ANALYSIS ON ENTRY CAPACITY AND OBSERVED MAXIMUM TRAFFIC FLOWS AT ROUNDABOUTS IN JAPAN

    KANBE Nobuto, ODAKA Shinji, KANG Nan, NAKAMURA Hideki, MORITA Hirohisa

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 71 ( 5 ) page: I_1017 - I_1025   2015

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    In recent years, field operational tests and implementation of roundabout are actively promoted at several places in Japan, and roundabout has been legally positioned through the amendment of the Road Traffic Act in June 2013. Entry capacity is one of the most important indices for performance evaluation related to the application of roundabouts. However, a criterion of entry capacity including impacts of pedestrians and cyclists based on the observation has not been available in Japan due to the limited observation examples. This paper aims to analyze characteristics of roundabout entry traffic flows based on the field data observed at several existing and/or experimental roundabouts. Entry capacity observed at Roppontsuji roundabout in Karuizawa Town is also examined and compared with the estimated values by a proposed entry capacity estimation model.

    DOI: 10.2208/jscejipm.71.i_1017

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  110. A STATISTICAL MODEL ANALYSIS ON TRAFFIC ACCIDENT FACTORS BASED ON ROAD TRAFFIC AND SOCIAL ENVIRONMENTAL CONDITIONS

    WATANABE Kazuki, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 71 ( 5 ) page: I_889 - I_901   2015

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    The objective of this study is to clarify a relationship between the road traffic conditions and accident frequency through statistical model analysis towards implementing effective safety measures. A rich accident database was combined with relevant road traffic information by using GIS software, and two different models, i.e. negative binomial regression and multiple regression models were independently applied for estimating accident frequency. As a result, it was found that accident frequency is closely related to average travel speeds and distance between intersections in arterial roads. Regarding non-arterial roads, the result specified different influencing factors by accident type. Furthermore, it suggested a high potential of frequent accident occurrence in non-arterial roads particularly at positions close to the arterial roads with low average travel speed. Finally, the necessity of improving quality of traffic flow and hierarchical road network for road safety was discussed.

    DOI: 10.2208/jscejipm.71.i_889

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  111. Application of social force model to pedestrian behavior analysis at signalized crosswalk

    Zeng, WL; Chen, P; Nakamura, H; Iryo-Asano, M

    TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES   Vol. 40   page: 143 - 159   2014.3

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    Limited pedestrian behavior models shed light on the case at signalized crosswalk, where pedestrian behavior is characterized by group or individual evasion with surrounding pedestrians, collision avoidance with conflicting vehicles, and response to signal control and crosswalk boundary. This study fills this gap by developing a microscopic simulation model for pedestrian behavior analysis at signalized intersection. The social force theory has been employed and adjusted for this purpose. The parameters, including measurable and non-measurable ones, are either directly estimated based on observed dataset or indirectly derived by maximum likelihood estimation. Last, the model performance was confirmed in light of individual trajectory comparison between estimation and observation, passing position distribution at several cross-sections, collision avoidance behavior with conflicting vehicles, and lane-formation phenomenon. The simulation results also concluded that the model enables to visually represent pedestrian crossing behavior as in the real world. © 2014 Elsevier Ltd.

    DOI: 10.1016/j.trc.2014.01.007

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  112. Estimation of Roundabout Entry Capacity Under the Impact of Pedestrians by Applying Microscopic Simulation

    Kang, N; Nakamura, H; Asano, M

    TRANSPORTATION RESEARCH RECORD   Vol. 2461 ( 2461 ) page: 113 - 120   2014

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    Entry capacity is one of the most important indexes for performance evaluation of roundabouts. In addition to circulating vehicles, pedestrian flow is another key conflicting stream that has a significant impact on entry capacity. Pedestrian impact is considered by an adjustment factor in the Highway Capacity Manual 2010. However, this method is limited in estimating pedestrian impact by several influencing factors [e.g., pedestrian approaching side, farside pedestrian recognition rate (FPRR) of drivers, and physical splitter island] that are considered to be significant for representing the characteristics of the Japanese situation. The impacts of these influencing factors are examined by microscopic simulation in this study. Results from the simulation study showed that under the condition without a physical splitter island, entry capacity was reduced more significantly when more pedestrians were from the farside of the crosswalk, whereas capacity relatively increased with decreasing FPRR. Moreover, entry capacity was also increased after the installation of a physical splitter Island. The significance and the necessity of a physical splitter island were demonstrated in this analysis for roundabout design and operation in Japan. This research also showed that those influencing factors (i.e., pedestrian approaching side, FPRR, and physical splitter island) should be coasidered in entry capacity estimation.

    DOI: 10.3141/2461-14

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  113. ANALYSIS OF RIGHT-TURN VEHICLE BEHAVIOR IN PROTECTED RIGHTTURN PHASE FOR PLANNING SIGNALIZED INTERSECTION IMPROVEMENT

    WATANABE Kazuki, NAKAMURA Hideki, IRYO-ASANO Miho

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 70 ( 5 ) page: I_1013 - I_1022   2014

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    It is of great importance to analyze right-turning behavior at signalized intersection given high accident records related to right-turn vehicles, which also helps provide valuable insights into safety assessment of signalized intersection. This study aims to analyze the right-turn vehicle behavior in protected right-turn phase by considering the influencing factors of geometric characteristics and signal operation. It was found based on empirical modeling results that the right-turn vehicle behavior is closely related to geometric characteristics such as intersection angle and setback distance of stop bar. Furthermore, in order to make a balance of both positive and negative impact, the potential strategies may bring upon safety performance of signalized intersection, all the influencing factors related to right-turn behavior were summarized and evaluated. Finally, the necessity of employing microscopic simulation to enable a comprehensive evaluation of surrogate safety meausure (SSM) at signalized intersection was examined.

    DOI: 10.2208/jscejipm.70.i_1013

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  114. MODELING PEDESTRIAN SPEED AT SIGNALIZED CROSSWALKS CONSIDERING CROSSWALK LENGTH AND PEDESTRIAN SIGNAL TIMING

    ZHANG Xin, NAKAMURA Hideki, IRYO-ASANO Miho, CHEN Peng

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 70 ( 5 ) page: I_1031 - I_1040   2014

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    Quantifying the effects of crosswalk length and signal timing on pedestrian walking speed is an important requirement for providing a rational safety assessment at signalized intersections. This study investigates the effects of pedestrian green time (PG), crosswalk length and pedestrian crossing direction on pedestrian walking speed at signalized crosswalk. It is assumed that the pedestrian walking speeds consist of two components v1 and v2 at two consecutive halves of crosswalk. Empirical analysis shows that the longer crosswalk tends to induce the higher walking speed. Pedestrian walking speed increases as PG proceeds. Furthermore, a comparison of pedestrian speed models for PG and PF (pedestrian flashing green time) demonstrates that pedestrian walking speeds at PF are higher and more variable than at PG. The sensitivity analysis helps understand how these models behave depending on change of each variable.

    DOI: 10.2208/jscejipm.70.i_1031

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  115. 横断歩行者を考慮したラウンドアバウト流入交通容量のシミュレーション分析 Reviewed

    中村 英樹

    国際交通安全学会誌IATSS Review   Vol. 39-1   page: 56 - 64   2014

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  116. Application of surrogate safety measures for assessment of pedestrian versus left-turning vehicle conflict at signalized crosswalks

    Chen P., Nakamura H., Asano M.

    Advances in Transportation Studies   Vol. 1 ( SPECIAL ISSUE ) page: 37 - 50   2014

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    Pedestrian safety improvement at signalized intersections remains a critical issue. The major threat comes from frequent interaction with turning vehicles, especially left-turners (left-hand traffic system). This study gains insights into how surrogate safety measure (SSM) can be utilized for pedestrian versus left-turning vehicle conflict assessment, and although a small step, how to relate SSM to limited crash records for crash risk estimation. Based on the video data collected at several crosswalks in Nagoya City, Japan, SSMs, i.e., Post Encroachment Time (PET) and vehicle passing speed at conflict point were extracted for analysis. PETs were estimated for both near-side and far-side approaching pedestrians by identifying the potential conflict points and considering the physical size of left-turning vehicles. The effectiveness of SSMs to reflect the impact of site-specific geometric characteristics and operational conditions upon conflict risk has been demonstrated. Furthermore, crash risk estimation models were developed by using Poisson regression methods based on mean PET, the number of short PETs per hour and average vehicle passing speed at conflict point at each crosswalk. It demonstrates that high turning speed, in conjunction with higher frequency of short PETs result in higher crash rates.

    DOI: 10.4399/97888548735445

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  117. A comparative study on crash-influencing factors by facility types on urban expressway

    Wu Y., Nakamura H., Asano M.

    Journal of Modern Transportation   Vol. 21 ( 4 ) page: 224 - 235   2013.12

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    This study aims at identifying crash-influencing factors by facility type of Nagoya Urban Expressway, considering the interaction of geometry, traffic flow, and ambient conditions. Crash rate (CR) model is firstly developed separately at four facility types: basic, merge, and diverge segments and sharp curve. Traffic flows are thereby categorized, and based on the traffic categories, the significances of factors affecting crashes are analyzed by principal component analysis. The results reveal that, the CR at merge segment is significantly higher than those at basic and diverge segments in uncongested flow, while the value is not significantly different at the three facility types in congested flow. In both un-and congested flows, sharp curve has the worst safety performance in view of its highest CR. Regarding influencing factors, geometric design and traffic flow are most significant in un-and congested flows, respectively. As mainline flow increases, the effect of merging ratio affecting crash is on the rise at basic and merge segments as opposed to the decreasing significance of diverging ratio at diverge segment. Meanwhile, longer acceleration and deceleration lanes are adverse to safety in uncongested flow, while shorter acceleration and deceleration lanes are adverse in congested flow. Due to its special geometric design, crashes at sharp curve are highly associated with the large centrifugal force and heavy restricted visibility. © The Author(s) 2013.

    DOI: 10.1007/s40534-013-0024-9

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  118. Stochastic approach for modeling the effects of intersection geometry on turning vehicle paths

    Alhajyaseen, WKM; Asano, M; Nakamura, H; Tan, DM

    TRANSPORTATION RESEARCH PART C-EMERGING TECHNOLOGIES   Vol. 32   page: 179 - 192   2013.7

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    Analytical evaluation techniques for the safety performance of signalized intersections are applicable to limited scenarios and conditions, whereas simulation-based analysis tools are very flexible and promising. This study is part of intensive efforts to develop a microscopic simulation model for the safety assessment of signalized intersections. One important aspect of analyzing driver maneuver is vehicle paths. Broadly varying paths may result in widely distributed potential conflict points with other movements, which may affect the occurrence probability of severe conflicts. Therefore, this study aims to develop a technique to reproduce the variations in the paths of turning vehicles, considering intersection geometry, vehicle type, and speed. Several signalized intersections in Nagoya City, Japan, with various traffic and geometric characteristics were videotaped. The analysis revealed that the paths of right-turning vehicles (left-hand traffic) are more sensitive to the vehicle speed and turning angle whereas those of left-turning vehicles are more sensitive to the intersection corner radius, turning angle, and vehicle speed. For modeling individual vehicle paths, this study applies the Euler-spiral-based approximation methodology where each trajectory is fitted by an entering Euler spiral curve followed by a circular curve and an exit Euler spiral curve. The proposed models are unique since they provide a realistic and rational representation of the variations in turning vehicles' paths inside intersections. © 2012 Elsevier Ltd.

    DOI: 10.1016/j.trc.2012.09.006

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  119. Left-turn gap acceptance models considering pedestrian movement characteristics

    Alhajyaseen, WKM; Asano, M; Nakamura, H

    ACCIDENT ANALYSIS AND PREVENTION   Vol. 50   page: 175 - 185   2013.1

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    Pedestrian-vehicle conflicts are considered as a common safety problem at signalized intersections. The threat to pedestrian safety is mainly related to the interaction with turning vehicles, especially left-turners (left-hand traffic system). This study aims to analyze the lag/gap acceptance behavior of left-turners considering pedestrian movement at signalized crosswalks. Furthermore, the severity of pedestrian-vehicle conflicts is addressed by analyzing vehicle speeds at the conflict points. User behavior at several signalized intersections in Japan is observed by using video cameras. It is assumed that pedestrian movements have their origin at either the near-side (the side of the exiting vehicular traffic) or far-side of the crosswalk. Accepted/rejected lags and gaps are extracted, classified depending on the direction of pedestrian movement, and modeled by using Cumulative Weibull distribution function. The results show that drivers tend to accept shorter lags/gaps between near-side pedestrians compared to far side pedestrians. Furthermore, drivers tend to accept short lags while being conservative about short gaps. Simultaneously vehicles clear the conflict area with significantly higher speeds when accepting lags with single pedestrians. This indicates that the conflicts that occur at low pedestrian demand levels are more severe compared to those at high demand levels. © 2012 Elsevier Ltd.

    DOI: 10.1016/j.aap.2012.04.006

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    PubMed

  120. Lane-Based Breakdown Identification at Diverge Sections for Breakdown Probability Modeling

    Ma, DP; Nakamura, H; Asano, M

    TRANSPORTATION RESEARCH RECORD   ( 2395 ) page: 83 - 92   2013

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    When the breakdown probability on expressways is being modeled, the identification of breakdowns is a decisive issue. To date, most identification methods have treated all lanes of the main line as one unit; these methods have been conducted mainly by checking the aggregated data of the cross section. However, this cross section-based method oversimplifies breakdown identification for expressway facilities, such as diverge sections, on which preferences for lane usage differ significantly. Therefore, a lane-based method is proposed to identify breakdowns in each lane; the timing of the breakdown is determined by a critical speed, which is optimized by obtaining the most significant speed reductions that accompany the breakdown. The proposed lane-based method is applied to four bottlenecks at diverge sections on intercity expressways in Japan. The superiorities of the lane-based method are as follows. First, the method can identify and exclude semicongested cases, in which some lanes are congested and others are not. At a diverge section of the Toyota junction in Japan, 15 semicongested cases were identified by the lane-based method from the 198 breakdowns identified by the cross section-based method. Second, the timing of a breakdown can be appropriately determined, as it was for 34 cases on this diverge section. These superiorities significantly improve the accuracy of extracted breakdown flow rates, which are underestimated by the existing cross section-based method. The breakdown probability is modeled with the lane-based method on the extracted breakdown flow rates, and the impacts of traffic condition characteristics are discussed. The diverge rate and the lane utilization rate are found to have significant impacts on the breakdown probability at diverge sections.

    DOI: 10.3141/2395-10

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  121. A Crash Risk Estimation Model for Urban Expressway Basic Segments Considering Geometry, Traffic Flow and Ambient Conditions

    WU Yong, NAKAMURA Hideki, ASANO Miho

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 10 ( 0 ) page: 1916 - 1929   2013

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    This study aims at developing a crash risk estimation model (CREM) considering the interaction of geometry, traffic flow and ambient conditions for basic segments of Nagoya Urban Expressway. A matched case-control study is firstly designed separately for three traffic conditions; low-density, high-density uncongested and congested regimes. Based on these case-control samples, conditional logistic regression is then applied and the CREM is finally developed. The results reveal that the model has statistical significance and acceptable goodness-of-fit, with 86.6%, 80.5% and 70.2% of predictive performance for each of the three traffic conditions, respectively. Regarding crash influencing factors, with the increase of traffic density, the significance of horizontal geometry affecting crash becomes lower. In contrast, the contribution of vertical geometry to crash risk is on the rise. Meanwhile, the effect of average speed on crashes gets more significant. Besides, nighttime or holiday can increase the relative risk compared to daytime or weekday, respectively.

    DOI: 10.11175/easts.10.1916

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  122. Effectiveness of Signal Coordination for Pedestrian Flows Considering Bi-directional Flow Impacts

    K.M. ALHAJYASEEN Wael, LI Meng, NAKAMURA Hideki, DAAMEN Winnie

    Asian Transport Studies   Vol. 2 ( 3 ) page: 223 - 238   2013

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    Existing signal control strategies do not consider pedestrian flows in optimizing signal parameters, which may impose significant delays on pedestrians. This study aims to investigate the rationality and effectiveness of designing signal coordination for pedestrians. A numerical case study in Japan is analyzed. Field survey is conducted to collect the geometric characteristics, signal timings and vehicular traffic condition information. In a parallel approach, the performances of signal coordination for vehicular and pedestrian traffic are estimated by using the vehicular traffic simulation tool Synchro/SimTraffic and the pedestrian simulation tool NOMAD. The results showed that the coordination for the major pedestrian flow led to a significant reduction in average delay (15%). Generally, it is concluded that the effectiveness of pedestrian signal coordination is not guaranteed but depends on the relationship between pedestrian platoon dispersion and the signal cycle length.

    DOI: 10.11175/eastsats.2.223

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  123. MODELING GAP CHOICE BEHAVIOR AT URBAN EXPRESSWAY MERGING SECTIONS

    CHU Tien Dung, NAKAMURA Hideki, ASANO Miho

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 69 ( 5 ) page: I_881 - I_891   2013

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    This paper proposes an approach to model the gap choice behavior of merging vehicles under various traffic flow conditions at urban expressway merging sections in Nagoya, Japan. The gap choice is classified into three patterns denoted direct, yield and chase merging. Empirical analysis shows that mainline traffic conditions significantly affect the proportion of gap choice. In addition, yield and chase choices result in further merging position compared to direct one. This fact is necessary to be considered in order to design the acceleration lane to meet driver behavior under relevant operational traffic flow conditions. TTC is adopted as an index to determine the threshold of choosing a merging pattern. The results show that the thresholds of choosing direct/yield or chase, continue to chase or not and direct or yield are 4.3, 3.2 and 5.4 seconds, respectively. The gap choice behavior is modeled by applying binary logit model. The results reveal that relative speed and space gap, traffic conditions, acceleration lane length, and remaining distance significantly affect the gap choice behavior of merging drivers.

    DOI: 10.2208/jscejipm.69.i_881

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  124. Estimation of left-turning vehicle maneuvers for the assessment of pedestrian safety at intersections

    Alhajyaseen W.K.M., Asano M., Nakamura H.

    IATSS Research   Vol. 36 ( 1 ) page: 66 - 74   2012.7

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    Improving pedestrian safety at intersections remains a critical issue. Although several types of safety countermeasures, such as reforming intersection layouts, have been implemented, methods have not yet been established to quantitatively evaluate the effects of these countermeasures before installation. One of the main issues in pedestrian safety is conflicts with turning vehicles. This study aims to develop an integrated model to represent the variations in the maneuvers of left-turners (left-hand traffic) at signalized intersections that dynamically considers the vehicle reaction to intersection geometry and crossing pedestrians. The proposed method consists of four empirically developed stochastic sub-models, including a path model, free-flow speed profile model, lag/gap acceptance model, and stopping/clearing speed profile model. Since safety assessment is the main objective driving the development of the proposed model, this study uses post-encroachment time (PET) and vehicle speed at the crosswalk as validation parameters. Preliminary validation results obtained by Monte Carlo simulation show that the proposed integrated model can realistically represent the variations in vehicle maneuvers as well as the distribution of PET and vehicle speeds at the crosswalk. © 2012 International Association of Traffic and Safety Sciences.

    DOI: 10.1016/j.iatssr.2012.03.002

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  125. Development of Microscopic Traffic Simulation Model for Safety Assessment at Signalized Intersections

    Tan, DM; Alhajyaseen, WKM; Asano, M; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   ( 2316 ) page: 122 - 131   2012

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    Language:Japanese   Publisher:Transportation Research Record  

    Because of traffic accidents at signalized intersections, improvement in the design of geometric layouts and operations of intersections is needed. Traffic simulation provides an innovative approach to assessing the safety performance of various layouts and operational policies of signalized intersections. A microscopic simulation model was developed to assess the safety of signalized intersections. The proposed simulation model integrates many key behavioral models of road users, such as the stop-go decision at the onset of a yellow light, turning paths, turning speeds, start-up response time, and pedestrian gap acceptance models. The main feature of these empirical models is their consideration of the stochastic behavior of road users. Furthermore, these models are sensitive to the layout and operation of signalized intersections. This paper discusses how conflicts are presented inside the simulation by demonstrating the mechanism of one of the conflicts. Model validation and a case study were conducted. The validation results show that the simulation model reasonably represents the occurrence of conflicts at signalized intersections, which proves that the proposed model can be a reliable approach to safety assessment. A case study compares the performance of compact intersections with wider layouts. The simulation results show trends in safety improvements, although a general conclusion cannot be made.

    DOI: 10.3141/2316-14

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  126. EVALUATION OF THE FUNCTIONALLY HIERARCHICAL ROAD NETWORK CONSIDERING JUNCTION TYPES

    GOTO Azusa, NAKAMURA Hideki, ASANO Miho

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 68 ( 5 ) page: I_751 - I_764   2012

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    A concept of the functionally hierarchical road network has been recognized with the purpose to provide the required service for road of each class. Especially in Japan, practical use of this concept has been intensively discussed from the viewpoint of both mobility improvement of arterial roads and traffic calming in local streets. However, the impact of junctions, which is regarded as a key issue of the hierarchical road network, has not been quantitatively evaluated with the performance of individual roads and further the entire network at planning stage. Therefore, in this paper, a methodology to evaluate the impacts of junction types on the performance of the network is developed by considering junction delay into user equilibrium assignment. By applying it, case studies with hypothetical grid network showed that reduction in junction delays at arterial roads is significant to realize hierarchical road network; and if it is achieved, traffic calming in local roads can also effectively work.

    DOI: 10.2208/jscejipm.68.i_751

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  127. A COMPARISON ANALYSIS ON CO2 EMISSION WITH ROUNDABOUTS AND SIGNALIZED INTERSECTIONS BASED ON THE DRIVING TESTS

    YOSHIOKA Keisuke, YONEYAMA Yoshiyuki, MUNEHIRO Kazunori, NAKAMURA Hideki, OGUCHI Takashi

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 68 ( 5 ) page: I_1253 - I_1259   2012

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    Roundabouts have been focused as safer, ecological and economical grade intersection type, and the practical development of roundabouts is currently discussed in Japan.<br>As it is possible to pass through without any stopping if there is no vehicle at a circulating roadway in roundabouts, the fuel consumption may be decreased in idling or accelerating. However, the total CO<sub>2</sub> emission based on practical driving tests has not been reported.<br>In this study, the amount of CO<sub>2</sub> emission is estimated from driving tests at a test roundabout and existing signal intersection. As a result, it is shown that the total CO<sub>2</sub> emission from the roundabout is decreased compared to the signal intersection.

    DOI: 10.2208/jscejipm.68.i_1253

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  128. Investigating Operational Benefits of Group-based Signal Control in Japan Through a Stochastic Approach

    Tang K., Nakamura H.

    International Journal of Intelligent Transportation Systems Research   Vol. 9 ( 2 ) page: 71 - 81   2011.5

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    Publisher:International Journal of Intelligent Transportation Systems Research  

    This study intends to investigate operational performance of the group-based signal control approach (GA) in Japan. A cycle-based stochastic approach incorporating the HCM 2000 delay model and Monte Carlo simulation was proposed. To facilitate its application, extensive field data was collected at 11 typical intersections in Germany and Japan to understand the variability of input variables and their correlations. A series of case studies were eventually conducted to investigate the applicability of GA under various conditions, i. e., degree of saturation (DS), split ratio (SR), and the coefficient of variation (COV) of traffic demand. Conclusions supported that the operational performance of GA deteriorated with increasing SR and decreasing DS. GA is apparently advantageous for SRs less than 0.8, COVs less than 0.2, and optimum cycle lengths greater than 90 s. © 2011 Springer Science+Business Media, LLC.

    DOI: 10.1007/s13177-011-0028-y

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  129. Modeling and Implementation of Adaptive Transit Signal Priority on Actuated Control Systems

    Li, M; Yin, YF; Zhang, WB; Zhou, K; Nakamura, H

    COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING   Vol. 26 ( 4 ) page: 270 - 284   2011.5

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    Publisher:Computer-Aided Civil and Infrastructure Engineering  

    This article describes the development and implementation of adaptive transit signal priority (TSP) on an actuated dual-ring traffic signal control system. After providing an overview of architecture design of the adaptive TSP system, the article presents an adaptive TSP optimization model that optimizes green splits for three consecutive cycles to minimize the weighted sum of transit vehicle delay and other traffic delay, considering the safety and other operational constraints under the dual-ring structure of signal control. The model is illustrated using a numerical example under medium and heavily congested situations. The findings from a field operational test are also reported to validate and demonstrate the developed TSP system. At a congested intersection, it is found that the average bus delay and average traffic delay along the bus movement direction were reduced by approximately 43% and 16%, respectively. Moreover, the average delay of cross-street traffic was increased by about 12%. © 2010 Computer-Aided Civil and Infrastructure Engineering.

    DOI: 10.1111/j.1467-8667.2010.00677.x

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  130. Saturation Flow Rate Analysis for Shared Left-turn Lane at Signalized Intersections in Japan

    Chen Peng, Nakamura Hideki, Asano Miho

    6TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE   Vol. 16   page: 548 - 559   2011

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    Language:Japanese   Publisher:Procedia - Social and Behavioral Sciences  

    This study investigates stochastic saturation flow rate in Japan starting from shared permissive left-turn lane. The methods used in Highway Capacity Manual 2000 and Japan Society of Traffic Engineering (JSTE) guideline were analyzed and evaluated. The comparison results show that both HCM and JSTE tend to overestimate the performed saturation flow rate in shared left-turn lane. As for detailed analysis, lane blockage probability is interpreted by using a binary logistic regression model. Then an empirical model is proposed to test the effect of lane blockage and significant influencing factors on saturation flow rate estimation in shared left-turn lane. © 2011 Published by Elsevier Ltd.

    DOI: 10.1016/j.sbspro.2011.04.475

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  131. ANALYSIS ON PEDESTRIAN SPEEDS AT INTERSECTIONS CONSIDEREING SIGNAL TIMING AND CROSSWALK LENGTH

    Alhajyaseen Wael K. M., Zhang Xin, Nakamura Hideki, Asano Miho

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2011 ( 0 ) page: 105 - 105   2011

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    Quantifying the effects of signal timing and crosswalk geometry on pedestrian speed is an important requirement for improving existing operational policies and for providing a rational safety assessment at signalized intersections. The objective of this paper is to macroscopically investigate the effects of signal timing, crosswalk length and pedestrian origin-destination on pedestrian speed at signalized crosswalks. Three signalized crosswalks in Nagoya City are videotaped. A pre-developed data processing program is utilized to extract speed data. Pedestrian signal timing is divided into six intervals. Depending on the entering time, each pedestrian is assigned to one of the intervals. Then the speed distributions in different time interval are estimated and compared. Generally, it is concluded the entering speeds of pedestrians increase as pedestrian green interval proceeds. Moreover, pedestrians show higher travel speeds at long crosswalks.

    DOI: 10.11175/eastpro.2011.0.105.0

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  132. Analysis on the Variation of Left-Turning Vehicle Spatial Trajectories Inside Intersections

    Alhajyaseen Wael K. M., Asano Miho, Suzuki Kazufumi, Nakamura Hideki

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2011 ( 0 ) page: 309 - 309   2011

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    Although several safety countermeasures such as reforming intersection layouts have been implemented, methods to evaluate their effects prior to installation has not yet been established. One of the important safety issues at signalized intersections is the interaction between left-turning vehicles (left-hand traffic) and pedestrians/cyclists. This paper aims to analyze and model the trajectory variations of left-turning vehicles. Vehicle trajectories are collected at several signalized intersections with various traffic and geometric characteristics by video observations. The analysis reveals a significant variation in trajectories depending on intersection angle, number of exit lanes and vehicle type. For modeling individual vehicle trajectories and their distribution, the Euler-spiral-based approximation methodology is applied. Model validation showed that estimated trajectory distributions explain well the spatial maneuver of left-turning vehicles.

    DOI: 10.11175/eastpro.2011.0.309.0

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  133. A STUDY ON IMPLEMENTATION POLICY OF AUXILIARY PASSING LANE ON TWO-WAY TWO-LANE HIGHWAYS CONSIDERING FOLLOWER DENSITY

    NAKAMURA Hideki, KOBAYASHI Masato, CATBAGAN Jerome L.

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 67 ( 3 ) page: 270 - 282   2011

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     In this paper, a methodology to evaluate impacts of implementing auxiliary passing lanes on the qulity of service of two-way two-lane (TWTL) highways is developed, by adopting follower density as a measure of effectiveness. It aims to quantitatively esti mate the performance of traffic flows to be realized dependent on the passing lane length and its spacing and to provide suggestions as a design guide. Relationships between passing lane length, one-lane section length and follower density are formulated by modeling the simulation results based on traffic fl ow surveys. And possible combinations of minimum required passing lane length and its spacing required for achieving the target performance are indicated. Furthermore, the expected qulity of service of traffic flow under seve ral typical design policies of 2+1 lane highways are evaluated by applying this concept.

    DOI: 10.2208/jscejipm.67.270

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  134. REVIEW AND PERSPECTIVE OF HIGHWAY CAPACITY AND QUALITY OF SERVICE RESEARCH IN JAPAN

    OGUCHI Takashi, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 67 ( 3 ) page: 217 - 229   2011

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     The highway traffic congestion is one of the most important social and technical issues from the early days of motorization in Japan. Accordingly, the highway capacity has long been a major concern of traffic engineers, not only in research but also in practice, in order to alleviate the traffic congestions. Also, the concept of the quality of service of traffic flow and its proper understanding according to diverse conditions are crucial for implementing the performance-oriented highway planning and design schemes. This article therefore overviews the recent research works regarding highway capacity and quality of service particularly in Japan, after reviewing the state of the arts in bottleneck phenomena observed on Japan motorways and highways. And the future perspective of these research fields is discussed.

    DOI: 10.2208/jscejipm.67.217

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  135. EDITORIAL - TOWARDS PRACTICAL APPLICATION OF THE PERFORMANCE-ORIENTED HIGHWAY PLANNING AND DESIGN

    NAKAMURA Hideki, OGUCHI Takashi

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 67 ( 3 ) page: 195 - 202   2011

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     Quality of road traffi c in Japan is still unsatisfactory as the road network cannot achieve the desirable performance corresponding to traffi c and access functions of roads yet, and there remain a lot of subjects to be resolved in terms of road design and traffi c operations. The existing road network should be gradually improved and restructured as cost-effective, high-performance one, however, the conventional highway planning and design methodology can be considered to hardly achieve it. For that, practical application of the "performance-oriented highway planning and design" policy is needed, which can flexibly adopt possible combinations of road design and traffi c operation schemes necessary for realizing target performance. In this article, for the special issue on "performance-oriented highway planning and design", its concept and research requirements are overviewed, as well as the structure of this issue.

    DOI: 10.2208/jscejipm.67.195

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  136. STUDY ON THE ESTIMATION OF SPEED-FLOW RELATIONSHIPS FOR DIVIDED TWO-WAY TWO-LANE EXPRESSWAY SECTIONS

    UTSUMI Taisuke, HAMAOKA Hidekatsu, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 67 ( 3 ) page: 261 - 269   2011

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     A divided two-way two-lane (TWTL) expressway crosssection was defined in the most recent update of Road Structure Ordinance in 2003. This novel structure is expected to contribute to saving building cost of rural expressways particularly with low traffic demands. However, since its speed performance is remained unclear, the expected target speed may not be realized under some road traffic conditions.<br> This paper therefore aims to analyze impacts of various conditions on speed-flow relationships of the divided TWTL expressway sections by using vehicle detector data, towards implementing the performance-oriented planning and design policy. After extensive analyses on several influencing factors that affect speed performance such as heavy vehicle ratio and precipitation, speed-flow relationships under different conditions are finally formulated. By using the proposed formulae, speed performance of the TWTL expressway sections can be verified at the planning and design stage of highways.

    DOI: 10.2208/jscejipm.67.261

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  137. Urban Expressway Capacity Characteristics of Lane Closure Sections due to Accidents

    MA Danpeng, NAKAMURA Hideki, ASANO Miho

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 9 ( 0 ) page: 1286 - 1299   2011

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    This paper investigates urban expressway capacity characteristics of lane closure sections due to accidents. Methodology includes the following parts: 1) identification of a breakdown due to an accident, 2) estimation of capacity under accident conditions, 3) exploring features of capacity drop percentage, and 4) fitting probability distribution of capacity drop percentage. Accident record data and loop detector data on Odaka Route of Nagoya Expressway during three years are utilized to fulfill the investigation. The results reveal that mean capacity value increases and its variance turns to be convergent with increase of lane closure duration. Accident types like multiple rear-end collisions and rear-end collisions result in comparatively greater values of capacity drop percentage. Also accidents on curve segments bring relatively higher capacity drops compared with those on straight segments. Furthermore, capacity drop percentage is shown to be stochastic, and Beta distribution can well fit its probability distribution.

    DOI: 10.11175/easts.9.1286

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  138. Start-up Behavior Considering Interactions between the Clearing and Entering Vehicles during the Signal Change and Clearance Intervals

    Suzuki Kazufumi, Goto Azusa, Nakamura Hideki, Tang Keshuang, Asano Miho

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2011 ( 0 ) page: 306 - 306   2011

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    The signal change and clearance intervals, more specifically the all-red times, are often set longer than necessary in Japan. Too long all-red times not only increase lost time but also may induce aggressive pass and lead to safety drop. Hence, the objective of this study is to investigate the impacts of intersection geometry, signal control, and traffic conflicts on driver's start-up behavior during the signal change and clearance intervals. By using extensive field data, stochastic models are developed for estimating the distributions of starting response time (SRT) and acceleration rate of the entering vehicles. A numerical examination is performed to explore the possibility of reducing the length of all-red times when the aforementioned impacts on start-up behavior are incorporated into the calculation procedure. Conclusions support that the minimum required all-red times can be reduced by 1 second.

    DOI: 10.11175/eastpro.2011.0.306.0

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  139. Impacts of Channelization Islands on the Left-turning Vehicle Maneuvers at Signalized Intersections in Japan

    TAN Dang minh, ASANO Miho, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 9 ( 0 ) page: 1938 - 1952   2011

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    The number of pedestrian injuries and fatalities involved by left-turning vehicles (in left-hand traffic) at signalized intersections occupies a very large portion in traffic accidents. Installing channelization islands, e.g. raised islands or zebra marking islands at intersections is considered as one of the most important factors influencing on conflicts between pedestrians and left-turning vehicles. However, their impacts on vehicle maneuvers have not been quantitatively analyzed. The objective of this study, therefore, is to quantitatively evaluate the impacts of channelization islands, on maneuvers of left-turning vehicles. Results of the analyses on turning vehicle maneuvers conclude that the use of raised islands gives between one-and-a-half to two times greater impacts on the trajectory and the speeds as compared to the impacts of zebra islands. The use of zebra marking islands has low influence on the vehicle trajectory and the speed.

    DOI: 10.11175/easts.9.1938

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  140. Effectiveness of Signal Coordination for Pedestrian Flows Considering Bi-directional Flow Impacts

    Alhajyaseen Wael K. M., Li Meng, Nakamura Hideki, Daamen Winnie

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2011 ( 0 ) page: 225 - 225   2011

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    Existing signal control strategies do not consider pedestrian flows in optimizing signal parameters, which may impose significant delays on pedestrians. This study aims to investigate the rationality and effectiveness of designing signal coordination for pedestrians. A Japanese numerical case study is analyzed. Field survey is conducted to collect the geometric characteristics, signal timings and vehicular traffic condition information. In a parallel approach, the performances of signal coordination for vehicular and pedestrian traffic are estimated by using the vehicular simulation tool Synchro/SimTraffic and the pedestrian simulation tool NOMAD. The results showed that the coordination for the major pedestrian flow led to a significant reduction in average delay (15%). Generally, it is concluded that the effectiveness of pedestrian signal coordination is not guaranteed but depends on the relationship between pedestrian platoon dispersion and the signal cycle length.

    DOI: 10.11175/eastpro.2011.0.225.0

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  141. APPLICATION OF TRAVEL TIME RELIABILITY FOR PERFORMANCE ORIENTED OPERATIONAL PLANNING OF EXPRESSWAYS

    MEHRAN Babak, NAKAMURA Hideki

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 67 ( 3 ) page: 283 - 299   2011

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     Evaluation of impacts of congestion improvement scheme s on travel time reliability is very significant for road authorities since travel time reliability repr esents operational performance of expressway segments. In this paper, a methodology is presented to estimate travel tim e reliability prior to implementation of congestion relief schemes based on travel time variation modeling as a function of demand, capacity, weather conditions and road accident s. For subject expressway segmen ts, traffic conditions are modeled over a whole year considering demand and capacity as random variables. Patterns of demand and capacity are generated for each five minute interval by appl ying Monte-Carlo simulation technique, and accidents are randomly generated based on a model that links acci dent rate to traffic conditions. A whole year analysis is performed by comparing de mand and available capacity for each scenario and queue length is estimated through shockwave analysis for each time in terval. Travel times are estimated from refined speed-flow relationships developed for intercity expressways and buffer time index is estimated consequently as a measure of travel time reliability. For validation, estimated reliability indices are compared with measured values from empirical data, and it is shown that the proposed method is suitable for operational evaluation and planning purposes.

    DOI: 10.2208/jscejipm.67.283

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  142. Analysis on the Variation of Left-turning Vehicle Spatial Trajectories Inside Intersections

    ALHAJYASEEN Wael K.M., ASANO Miho, SUZUKI Kazufumi, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 9 ( 0 ) page: 1543 - 1557   2011

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    Although several safety countermeasures such as reforming intersection layouts have been implemented, methods to evaluate their effects prior to installation has not yet been established. One of the important safety issues at signalized intersections is the interaction between left-turning vehicles (left-hand traffic) and pedestrians/cyclists. This paper aims to analyze and model the trajectory variations of left-turning vehicles. Vehicle trajectories are collected at several signalized intersections with various traffic and geometric characteristics by video observations. The analysis reveals a significant variation in trajectories depending on intersection angle, number of exit lanes and vehicle type. For modeling individual vehicle trajectories and their distribution, the Euler-spiral-based approximation methodology is applied. Model validation showed that estimated trajectory distributions explain well the spatial maneuver of left-turning vehicles.

    DOI: 10.11175/easts.9.1543

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  143. A STUDY ON THE STOPPING CHARACTERISTICS OF KISS-AND-RIDE VEHICLES IN STATION PLAZAS

    Journal of Japan Society of Civil Engineers, Ser. D3 (Infrastructure Planning and Management)   Vol. 67 ( 5 ) page: 67_I_1079 - 67_I_1087   2011

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    Station plazas are important interchanges in the transportation network. However in Japan, their performance is reduced due to insufficient consideration of K&R behavior. Accordingly this study aims to analyze K&R vehicle stopping characteristics by investigating influencing factors such as facility configuration and plaza structure. Based on empirical data, the stopping position choice is modeled. Also different influencing factors are found for picking-up and dropping-off vehicles. Furthermore, a case study is conducted by simulation to represent the stopping position choice influenced by barrier or facility configuration.

    DOI: 10.2208/jscejipm.67.67_i_1079

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  144. Unsteady Queue Discharge Characteristics of Shared Left-turn Lane at Signalized Intersections in Japan

    CHEN Peng, NAKAMURA Hideki, ASANO Miho

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2011 ( 0 ) page: 300 - 300   2011

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    In Japan, where vehicles travel on the left side of the road, the queue discharge rates of shared left-turn lane usually show comparable fluctuation, due to different departure characteristics of through and left-turning vehicles as well as interactions with pedestrians and bicycles. For a better evaluation of signalized intersections and then corridor performance, this study investigates stochastic queue discharge rates starting from shared left-turn lane and empirically explores its implications. Results show that efficient utilization of shared lane by through traffic can significantly improve discharge rate. At lower and higher pedestrian-bicycle volumes, discharge rates are relatively reliable. While at middle levels of pedestrian demands, more random arrivals and interactions lead to rather unstable saturation flow rate fluctuation. For the shared lane with a larger left turning radius, its discharge rates display a stable trend.

    DOI: 10.11175/eastpro.2011.0.300.0

    CiNii Research

  145. Unsteady Queue Discharge Characteristics of Shared Left-turn Lane at Signalized Intersections in Japan

    CHEN Peng, NAKAMURA Hideki, ASANO Miho

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 9 ( 0 ) page: 1499 - 1512   2011

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    In Japan, where vehicles travel on the left side of the road, the queue discharge rates of shared left-turn lane usually show comparable fluctuation, due to different departure characteristics of through and left-turning vehicles as well as interactions with pedestrians and bicycles. For a better evaluation of signalized intersections and then corridor performance, this study investigates stochastic queue discharge rates starting from shared left-turn lane and empirically explores its implications. Results show that efficient utilization of shared lane by through traffic can significantly improve discharge rate. At lower and higher pedestrian-bicycle volumes, discharge rates are relatively reliable. While at middle levels of pedestrian demands, more random arrivals and interactions between pedestrians and vehicles lead to rather unstable saturation flow rate fluctuation. For the shared lane with a larger left turning radius, its discharge rates display a stable trend. A comparative analysis between observed saturation flow rates, Highway Capacity Manual (HCM, 2000) and Japanese guideline (JSTE, 2007) estimations indicate both HCM and Japanese guideline usually overestimate the discharge rates in shared left-turn lane in Japan.

    DOI: 10.11175/easts.9.1499

    CiNii Research

  146. Impacts of Channelization Islands on the Left-turning Vehicle Maneuvers at Signalized Intersections in Japan

    Dang Minh Tan, Asano Miho, Nakamura Hideki

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2011 ( 0 ) page: 380 - 380   2011

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    The number of pedestrian injuries and fatalities involved by left-turning vehicles (in left-hand traffic) at signalized intersections occupies a very large portion in traffic accidents. Installing channelization islands, e.g. raised islands or zebra marking islands atintersections is considered as one of the most important factors influencing on conflicts between pedestrians and left-turning vehicles. However, their impacts on vehicle maneuver have not been quantitatively analyzed. The objective of this study, therefore, is to quantitatively evaluate the impacts of channelization islands, on maneuvers of left-turning vehicles. Results of the analyses on turning vehicle maneuvers conclude that the use of raised island gives between one-and-a-half to two times greater impacts on the trajectory and the speeds as compared to the impacts of zebra islands. The use of zebra marking islands has low influence on the vehicle trajectory and the speed.

    DOI: 10.11175/eastpro.2011.0.380.0

    CiNii Research

  147. Quality of pedestrian flow and crosswalk width at signalized intersections

    Alhajyaseen W., Nakamura H.

    IATSS Research   Vol. 34 ( 1 ) page: 35 - 41   2010.7

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    Publisher:IATSS Research  

    Among various pedestrian facilities, signalized crosswalks are the most complex and critical ones. Their geometry and configuration including width, position and angle directly affect the safety, cycle length and resulting delays for all users. Existing manuals do not provide clear and rational specifications for the required crosswalk width under different pedestrian demand combinations and properties. Furthermore, they do not consider the bi-directional flow effects on crossing speed and time when addressing pedestrian flow at signalized crosswalks. However, quantifying the effects of such interactions on the behavior of pedestrian flow is a prerequisite for improving the geometric design and configuration of signalized crosswalks. The objective of this paper is to develop a methodology for estimating the required crosswalk width at different pedestrian demand combinations and a pre-defined LOS. The developed methodology is based on theoretical modeling for total pedestrian platoon crossing time, which consists of discharge and crossing times. The developed models are utilized to generate the fundamental diagrams of pedestrian flow at signalized crosswalks. A comprehensive discussion about the effects of bi-directional flow and various pedestrian age groups on the characteristics of pedestrian flow and the capacity of signalized crosswalks is presented. It is found that the maximum reduction in the capacity of signalized crosswalks occurs at roughly equal pedestrian flows from both sides of the crosswalk. By utilizing existing LOS thresholds for pedestrian flow at signalized crosswalks, the required crosswalk widths for various pedestrian demand combinations are proposed for implementation. © 2010 International Association of Traffic and Safety Sciences.

    DOI: 10.1016/j.iatssr.2010.06.002

    Scopus

  148. Estimating the Minimum Required Width of Signalized Crosswalks Considering Bi-Directional Pedestrian Flow and Different Age Groups

    ALHAJYASEEN Wael K.M., NAKAMURA Hideki

    Asian Transport Studies   Vol. 1 ( 2 ) page: 181 - 198   2010

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    Existing manuals do not provide clear specifications for the required crosswalk width under different pedestrian demand volumes and characteristics. However, optimizing crosswalk configurations including width is an important concern to improve the overall performance of signalized intersections. The objective of this paper is to develop a methodology for estimating minimum required crosswalk width at different pedestrian demand volumes considering bi-directional flow and different pedestrian age groups. The developed methodology is based on modeling total pedestrian platoon crossing time which consists of discharge and crossing times. Discharge time is modeled by using shockwave theory while crossing time is modeled by applying aerodynamic drag theory. The developed models are then calibrated for crosswalks with mainly elderly or pupil pedestrian platoons. A set of criteria based on pedestrian crossing speed is developed to identify the minimum required crosswalk width. Finally, different required crosswalk widths are proposed for different pedestrian demand volumes and directional split ratios considering the effects of pupil and elderly pedestrian platoons.

    DOI: 10.11175/eastsats.1.181

    CiNii Research

  149. An Improved Follower Recognition Procedure to Estimate Follower Flow-Based Quality of Service Measures

    CATBAGAN Jerome, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 8 ( 0 ) page: 1822 - 1837   2010

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    For a follower-based service measure to be effectively used for two-lane highway quality of service evaluation, a more reliable follower identification procedure is necessary. Current follower recognition methodologies are based on single critical headway values that may not accurately identify followers since they do not take into account the randomness of preferred tracking headways and drivers' desired speeds. This paper presents an improved, probability-based follower identification methodology that takes both of these factors into account while also considering their variability across different driving conditions. The calculated follower percentage and follower density values were compared with those estimated using the 3-second threshold suggested by the HCM. The proposed methodology estimated more followers, particularly during periods of heavy flow, highlighting the inability of using a single headway value to correctly identify followers. The resulting follower counts have been normalized, making it possible to theoretically identify followers at any given time or driving condition.

    DOI: 10.11175/easts.8.1822

    CiNii Research

  150. An Improved Follower Recognition Procedure to Estimate Follower Flow-Based Quality of Service Measures Reviewed

    Catbagan, J.L. and Nakamura, H.

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. Vol. 7   page: 16 pages in CD-ROM   2009.11

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  151. *Modeling and Analysis of Pedestrian Flow at Signalized Crosswalks Reviewed

    Alhajyaseen, K.M.W. and Nakamura, H.

      Vol. Vol.26   page: 611-620   2009.11

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  152. Estimating the Minimum Required Width of Signalized Crosswalks Considering Bi-directional Pedestrian Flow and Different Age Groups Reviewed

    Alhajyaseen, K.M.W. and Nakamura, H.

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. Vol.7   page: 16 pages in CD-ROM   2009.11

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  153. Estimation of Crosswalk Width to Minimize Cycle Length at Signalized Intersections Reviewed

    Alhajyaseen, Wael K. M. and Nakamura, H.

    Proceedings of the Eleventh International Summer Symposium, JSCE     page: 213-216   2009.9

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  154. Traffic Signal Control Optimization from the Viewpoint of Emission at Isolated Intersections

    Ma, D. and Nakamura, H.

      Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  155. Assessing Impacts of Congestion Relief Schemes on Expressway Traffic Operations through Travel Time Reliability Analysis

    Mehran, B. and Nakamura, H.

    TRB 2nd international Symposium on Freeway and Tollway Operations     page: 12 pages   2009.6

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  156. *Considering Travel Time Reliability and Safety for Evaluation of Congestion Relief Schemes on Expressway Segments Reviewed

    Mehran, B. and Nakamura, H.

    IATSS Research   Vol. Vol.33 ( No.1 ) page: 55-70   2009.6

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  157. 幹線街路における沿道アクセス機能に応じた旅行速度性能曲線の定式化

    早河辰郎・中村英樹

    土木計画学研究・講演集   Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  158. 往復2車線道路における付加追越車線の設置水準に関する研究

    小林正人・中村英樹

    土木計画学研究・講演集   Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  159. 信号交差点における幾何構造と進入条件を考慮した右折走行軌跡のモデル化

    鈴木一史・中村英樹・石黒公規

    土木計画学研究・講演集   Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  160. 日本におけるラウンドアバウトの交通容量と遅れの推定方法に関する考察

    吉岡慶祐・中村英樹

    土木計画学研究・講演集   Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  161. 階層型道路ネットワークへの再編に向けて

    下川澄雄・内海泰輔・中村英樹・大口 敬

    土木計画学研究・講演集   Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  162. Effects of Bi-directional Flow and Different Pedestrian Age-Groups on Capacity of Signalized Crosswalks

    Alhajyaseen, K.M.W. and Nakamura, H.

      Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  163. Assessing Impacts of Hard Shoulder Utilization on Travel Time Reliability and Safety

    Mehran, B. and Nakamura, H

      Vol. No.39   page: 4ページ,CD-ROM   2009.6

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  164. 平面交差点の設計・運用方針の再考,巻頭言

    中村英樹

    交通工学   Vol. Vol.44, No.3   page: 1-2   2009.5

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  165. 日本におけるラウンドアバウトの計画・設計ガイドの検討

    中村英樹・大口 敬・馬渕太樹・吉岡慶祐

    交通工学   Vol. Vol.44 ( No.3 ) page: 24-33   2009.5

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  166. *複数ボトルネックを含む高速道路区間における渋滞現象の確率的解析 Reviewed

    稲野 晃・中村英樹・内海泰輔

    高速道路と自動車   Vol. 第52巻 ( 第1号 ) page: 19-29   2009.1

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  167. A Probabilistic Approach to Evaluate Safety during Intergreen Intervals at Signalized Intersections

    Tang, K. and Nakamura, H.

    88th TRB Annual Meeting     page: 24 pages, DVD-ROM   2009.1

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  168. Catbagan, J. L. and Nakamura, H. Reviewed

    *Probability-Based Follower Identification in Two-Lane Highways

    88th TRB Annual Meeting     page: 15 pages, DVD-ROM   2009.1

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  169. A Methodology for Modeling Pedestrian Platoon Discharge and Crossing Times at Signalized Crosswalks

    Alhajyaseen, W. K. M. and Nakamura, H.

    88th TRB Annual Meeting     page: 18 pages, DVD-ROM   2009.1

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  170. Methodology for Assessing Impacts of Congestion Relief Schemes on Travel Time Reliability

    Mehran, B. and Nakamura, H.

    88th TRB Annual Meeting     page: 18 pages, DVD-ROM   2009.1

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  171. *Desired Speed Distributions on Two-Lane Highways under Various Conditions Reviewed

    Catbagan, J. L. and Nakamura, H.

    , Transportation Research Record , Traffic Flow Theory and Characteristics, Transportation Research Board   Vol. No. 2088   page: 218-226   2009.1

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  172. Safety Evaluation for Intergreen Intervals at Signalized Intersections Based an Probabilistic Method

    Tang, KS; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   ( 2128 ) page: 226 - 235   2009

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    This study presents a probabilistic safety estimation approach based on traffic conflict technique. The study aims to investigate the impacts of the German signal control policy and intergreen design method on safety during intergreen intervals at signalized intersections in Japan. To facilitate application of the policy, the uncertainty of input variables and of safety itself, indicated by the postencroachment time, was analyzed first by means of field data collected at 12 typical intersections in Japan and Germany. A few case studies were then examined with Monte Carlo simulation. The results indicated that safety during the intergreen interval and its reliability might significantly drop if intergreen times were simply changed from the values based on the Japanese method to the values based on the German method without supplementary countermeasures. However, safety as well as reliability can be maintained if the Japanese control policy is completely replaced with the German one.

    DOI: 10.3141/2128-23

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    Scopus

  173. Implementing Travel Time Reliability for Evaluation of Congestion Relief Schemes on Expressways

    Mehran, B; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   ( 2124 ) page: 137 - 147   2009

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    Preevaluation of the impacts of congestion relief schemes on travel time reliability is significant for road authorities. However, most existing approaches to estimating travel time reliability rely mainly on empirical data and are therefore not of help for evaluating improvement schemes before implementation. A methodology is presented to estimate travel time reliability on the basis of modeling travel time variations as a function of demand, capacity, weather conditions, and road accidents. For a subject expressway segment, patterns of demand and capacity were generated for each 5-min interval during a year by using the Monte Carlo simulation technique, and accidents were generated randomly according to traffic conditions. A whole year analysis was performed by comparing demand and available capacity for each scenario; shock wave analysis was used to estimate the queue length at each time interval. Travel times were estimated from refined speed-flow relationships. The buffer time index was estimated as a measure of travel time reliability and compared with observed values from empirical data. After validation, the methodology was applied to assess the impact on travel time reliability of opening the hard shoulder to traffic. Opening the hard shoulder to traffic during the peak periods was found to ameliorate travel time reliability significantly and mitigate congestion levels, which could result in up to a 26% cut in the number of accidents occurring.

    DOI: 10.3141/2124-13

    Web of Science

    Scopus

  174. 日本におけるラウンドアバウトの計画・設計ガイドの検討 Reviewed

    中村 英樹, 大口 敬

    交通工学 44(3)     page: 24 - 33   2009

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  175. An Improved Follower Recognition Procedure to Estimate Follower Flow-Based Quality of Service Measures

    Catbagan Jerome Lejano, Nakamura Hideki

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2009 ( 0 ) page: 338 - 338   2009

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    Current follower recognition methodologies are based on single critical headway values that may not accurately identify followers since they do not take into account the randomness of preferred tracking headways and drivers desired speeds. This paper presents an improved, probability-based follower identification methodology that takes both of these factors into account while also considering their variability across different driving conditions. The calculated follower percentage and follower density values were compared with those estimated using the 3-second threshold suggested by the HCM. The proposed methodology estimated more followers, particularly during periods of heavy flow, highlighting the inability of using a single headway value to correctly identify followers. The resulting follower counts have been normalized, making it possible to theoretically identify followers at any given time or driving condition.

    DOI: 10.11175/eastpro.2009.0.338.0

    CiNii Research

  176. Evaluation of field experiment of group-based signal control in Japan

    Tang K., Nakamura H.

    16th ITS World Congress     2009

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    Publisher:16th ITS World Congress  

    This paper presents the evaluation results on operational and safety performance of group-based signal control, based on a field test undertaken in Japan recently. Starting response time (SRT), start-up lost time (SULT), clearance lost time (CLT), saturation flow rate (SFR), and approach delay (AD) are selected to represent operational performance. Certain occurrence frequencies and rates of stop-line crossing during amber (SCA) and red-light-running (RLR) act as the measures to safety performance during intergreen intervals. The results from the before-and-after analyses supported that the group-based control itself generally didn't significantly affect SRT, SULT, CLT, and SFR, while remarkably improved AD. Meanwhile, it substantially decreased SCA and RLR at the exclusive through and right-turn lanes. It reveals that both operational and safety benefits might be expected by applying such a policy.

    Scopus

  177. Estimating the Minimum Required Width of Signalized Crosswalks Considering Bi-directional Pedestrian Flow and Different Age Groups

    ALHAJYASEEN WAEL K. M., NAKAMURA HIDEKI

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2009 ( 0 ) page: 222 - 222   2009

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    Existing manuals do not provide clear specifications for the required crosswalk width under different pedestrian demands and properties. However, optimizing crosswalk configurations including width is an important concern to improve the overall performance of signalized intersections. The objective of this paper is to develop a methodology for estimating minimum required crosswalk width at different pedestrian demands considering bi-directional flow and different pedestrian age groups. The developed methodology is based on modeling total pedestrian platoon crossing time which consists of discharge and crossing times. Discharge and crossing times are modeled by using shockwave and aerodynamic drag theories respectively. Then developed models are calibrated for crosswalks with elderly or pupil pedestrian platoons. A criteria based on pedestrian crossing speed is developed to identify the minimum required crosswalk width. Finally, different minimum required crosswalk widths are proposed.

    DOI: 10.11175/eastpro.2009.0.222.0

    CiNii Research

  178. Signalized intersection design and operations: Experiences in Germany and Japan

    Tang K., Nakamura H.

    Proceedings of the 7th International Conference of Chinese Transportation Professionals Congress 2007: Plan, Build, and Manage Transportation Infrastructures in China     page: 520 - 529   2008.12

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    Publisher:Proceedings of the 7th International Conference of Chinese Transportation Professionals Congress 2007: Plan, Build, and Manage Transportation Infrastructures in China  

    An official nationwide manual on intersection planning and design remains absent in China. Presently, a research group led by Tongji University is addressing its first version. Toward gaining more profound knowledge on state of the art in intersection design and operations in overseas while developing Chinese manual, this paper thus presents German and Japanese experiences. Conclusions, future studies and efforts essential for China are discussed finally. © 2008 ASCE.

    DOI: 10.1061/40952(317)51

    Scopus

  179. IMPACTS OF GROUP-BASED SIGNAL CONTROL POLICY ON DRIVER BEHAVIOR AND INTERSECTION SAFETY

    TANG Keshuang, NAKAMURA Hideki

      Vol. 32 ( 2 ) page: 81 - 94   2008.11

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    CiNii Research

  180. Assessment of the Impacts of Opening the Hard Shoulder to Traffic on Travel Time Reliability

    Mehran, B. and Nakamura, H.

      Vol. No.38   page: 4ページ,CD-ROM   2008.11

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  181. A Proposed Methodology for Modeling Pedestrian Crossing Time at Signalized Crosswalks Considering Bi-directional Flow

    Alhajyaseen, W. and Nakamura,H.

      Vol. No.38   page: 4ページ,CD-ROM   2008.11

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  182. 実務者のための交通流調査講座,第5回 道路交通管理のための交通流調査 Reviewed

    鈴木一史・中村英樹

    交通工学   Vol. Vol.43, No.6   page: 82-89   2008.11

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  183. Impacts of Group-based Signal Control Policy on Driver Behavior and Intersection Safety Reviewed

    Tang, K. and Nakamura,H.

    IATSS Research   Vol. Vol.32, No.2   page: 81-94   2008.11

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  184. 遅れと環境負荷に基づく交通量の少ない平面交差部の最適制御方式の検討

    吉岡慶祐・中村英樹・馬渕太樹

    第28回交通工学研究発表会論文集     page: 37-40   2008.10

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  185. 幹線街路における走行性能照査型道路計画設計手法の構築

    内海泰輔・中村英樹・中井麻衣子・小出貴文

    第28回交通工学研究発表会論文集     page: 185-188   2008.10

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  186. *時間交通需要変動特性を考慮した交通性能照査型道路計画設計法 Reviewed

    内海泰輔・中村英樹

    土木計画学研究・論文集   Vol. Vol.25   page: 67-76   2008.9

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  187. 交差点安全性評価を目的とした2D ナノシミュレーションにおける利用者挙動の表現

    鈴木一史・中村英樹

    土木計画学研究・講演集   Vol. No.37   page: 4ページ,CD-ROM   2008.6

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  188. Applying Travel Time Reliability for Pre-Evaluation of Expressway Congestion Improvement Schemes

    Mehran, B. and Nakamura, H

      Vol. No.37   page: 4ページ,CD-ROM   2008.6

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  189. Operational Performance of Group-Based Signal Control Policy Under Various Traffic Conditions

    Tang, K. and Nakamura, H

    10th International Conference on Application of Advanced Technologies in Transportation   Vol. CD-ROM   page: Athens   2008.5

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  190. Two-Lane Highway Desired Speed Distributions under Various Conditions, 87th TRB Annual Meeting

    Catbagan, J.L. and Nakamura, H.

    Transportation Research Board     page: 10 pages, CD-ROM   2008.1

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  191. Characteristics of Breakdown Phenomenon in Merging Sections of Urban Expressways in Japan, Transportation Research Record

    Shawky, M. and Nakamura, H

    Transportation Research Board   Vol. No. 2012   page: 11-19   2008.1

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  192. Traffic Management in Japan, Thema Forschung

    Nakamura, H

    Das Wissenschaftsmagazin der Technischen Universitat Darmstadt     page: 62-64   2008

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  193. Transport policy and organization in Japan

    Enoch, M; Nakamura, H

    TRANSPORT REVIEWS   Vol. 28 ( 2 ) page: 159 - 180   2008

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    Language:Japanese   Publisher:Transport Reviews  

    In transport terms, Japan has an enviable reputation for operating effectively an incredibly complex road and rail system. However, relatively little is known about how this is done or about the issues that are facing policy-makers and shapers in the country. The purpose of this paper, then, is to investigate how land passenger transport is organized in Japan, and to begin to evaluate its effectiveness. This is done by drawing on a literature review and on findings from a scoping study based on a series of semi-structured in-depth interviews with key practitioners. Overall, the findings suggest that national and local transport policy in Japan faces a number of key challenges across all modes in the land passenger transport system, in particular relating to the fragmented approach to policy development, implementation, and operation and to the growing role of the car.

    DOI: 10.1080/01441640701526699

    Web of Science

    Scopus

  194. Desired Speed Distributions on Two-Lane Highways Under Various Conditions

    Catbagan, JL; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   ( 2088 ) page: 218 - 226   2008

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    Language:Japanese   Publisher:Transportation Research Record  

    On a two-lane highway with passing restrictions, user dissatisfaction usually is caused by the inability to drive at the desired speed because of a relatively slower lead vehicle. Although this condition clearly shows that vehicles in this state are following, current definitions of "following vehicle" are based mainly on headway alone. A "follower" can be more logically defined as a vehicle traveling below its desired speed because of the presence of a relatively slower lead vehicle. The problem arises because the desired speeds of different drivers vary significantly; the variation makes it difficult to assess whether a vehicle is constrained on the basis of directly accessible data alone. A study was done to develop desired speed distributions for various traffic, weather, and ambient conditions, which can be later used as input for simulation or to calculate a vehicle's following probability given its current speed. The collected data were classified according to different traffic, geometric, weather, and ambient conditions to form 64 data sets for analysis. The desired speed distributions were estimated by using the modified Kaplan-Meier approach and were found to be suitable for use as either simulation input or as a tool that can be used for follower identification. Differences between holiday and weekday travel speed preferences and effects of weather on driver speed choices were also found.

    DOI: 10.3141/2088-23

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    Scopus

  195. A Methodology of a Traffic-Performance-Oriented Highway Planning and Design Considering Hourly Traffic Demand fluctuation

    UTSUMI Taisuke, NAKAMURA Hideki

    INFRASTRUCTURE PLANNING REVIEW   Vol. 25 ( 25 ) page: 67 - 76   2008

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    Publisher:Japan Society of Civil Engineers  

    The existing highways in Japan are planned and designed based on the specifications determined in the past. However, economy and improvement of traffic-performance quality are demanded in the highways recently, and the authors have been advocating traffic-performance-oriented highway planning and design. In this paper, a methodology to estimate the traffic-performance of a planned inter-city highway throughout a year was established, and a traffic-performance-oriented highway planning and design methodology was proposed. This methodology provides several options of road crosssectional design for a planned highway, and makes it possible to adopt the most economical and best performing road structure and traffic operation option based on the latest knowledge

    DOI: 10.2208/journalip.25.67

    CiNii Research

  196. Impacts of group-based signal control policy on driver behavior and intersection safety

    Tang K., Nakamura H.

    IATSS Research   Vol. 32 ( 2 ) page: 81 - 94   2008

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    Publisher:IATSS Research  

    Unlike the typical stage-based policy commonly applied in Japan, the group-based control (often called movement-based in the traffic control industry in Japan) refers to such a control pattern that the controller is capable of separately allocating time to each signal group instead of stage based on traffic demand. In order to investigate its applicability at signalized intersections in Japan, an intersection located in Yokkaichi City of Mie Prefecture was selected as an experimental application site by the Japan Universal Traffic Management Society (UTMS). Based on the data collected at the intersection before and after implementing the group-based control policy respectively, this study evaluated the impacts of such a policy on driver behavior and intersection safety. To specify those impacts, a few models utilizing cycle-based data were first developed to interpret the occurrence probability and rate of red-light-running (RLR). Furthermore, analyses were performed on the yellow-entry time (Ye) of the last cleared vehicle and post encroachment time (PET) during the phase switching. Conclusions supported that the group-based control policy, along with certain other factors, directly or indirectly influenced the RLR behavior of through and right-turn traffics. Meanwhile, it has potential safety benefits as well, indicated by the declined Ye and increased PET values. © 2008 International Association of Traffic and Safety Sciences.

    DOI: 10.1016/S0386-1112(14)60211-9

    Scopus

  197. A Comparative Study on Traffic Characteristics and Driver Behavior at Signalized Intersections in Germany and Japan

    Tang, K. and Nakamura, H.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.7   page: 2470-2485   2007.12

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  198. Performance Evaluation of Roundabouts Considering Traffic Conflicts

    Nakamura, H. and Mabuchi, T.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.7   page: 2412-2424   2007.12

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  199. Influence of Heavy Vehicles on Japan Two-lane Highway Speed and Follower Flow Characteristics

    Catbagan, J.L. and Nakamura, H.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.7   page: 2533-2545   2007.12

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  200. Estimation Method of Hourly Traffic Demand Fluctuation throughout a Year for the Performance-oriented Highway Planning and Design Reviewed

      Vol. Vol.24   page: 825-834   2007.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  201. Determining Diameter and Circulatory Road Width of Roundabouts

      Vol. No.36   page: 4ページ,CD-ROM   2007.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  202. A Travel Speed Evaluation Method for Urban Arterials Based on Delay Estimations at Signalized Intersections

      Vol. No.36   page: 4ページ,CD-ROM   2007.11

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  203. An Analysis of Queuing Phenomena in an Intercity Expressway Section with a Range of Bottlenecks

      Vol. No.36   page: 4ページ,CD-ROM   2007.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  204. Three Aspects of Merging Capacity - Their Stochastic Nature Reviewed

    Shawky, M. and Nakamura, H.

    International Journal of ITS Research   Vol. Vol.5   page: 27-36   2007.10

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  205. A Study on Categorizing Traffic Demand Characteristics for the Performance Oriented Highway Planning and Design Reviewed

      Vol. Vol.42, No.5   page: 53-64   2007.9

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  206. Performance Evaluation of Highway Segments Using Travel Time Based Performance Measures Reviewed

    Mehran, B. and Nakamura, H.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.6   page: 10 pages   2007.9

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  207. Reproducing the Hourly Traffic Demand Fluctuation throughout a Year for the Evaluation of Highway Cross-section Design Reviewed

    Nakamura, H., Utsumi, T. and Watanabe, M

    Proceedings of the Eastern Asia Society of Transport Studies   Vol. Vol.6   page: 14 pages   2007.9

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  208. A Comparative Study on Traffic Characteristics and Driver Behavior at Signalized Intersections in Germany and Japan Reviewed

    Tang, K. and Nakamura, H.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.6   page: 16 pages   2007.9

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  209. Influence of Heavy Vehicles on Japan Two-lane Highway Speed and Follower Flow Characteristics Reviewed

    Catbagan, L.J. and Nakamura, H.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.6   page: 12 pages   2007.9

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  210. Performance Evaluation of Roundabouts Considering Traffic Conflicts Reviewed

    Nakamura, H. and Mabuchi, T.

    Journal of the Eastern Asia Society of Transport Studies   Vol. Vol.6   page: 12 pages   2007.9

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  211. An Analysis on Saturation Flow Rate and Its Variability

    Tang, K. and Nakamura, H

    11th World Conference on Transport Research     page: 19 pages in DVD   2007.6

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  212. A Study on Merging Capacity Fluctuation on Japan Urban Expressways

    Shawky, M. and Nakamura, H.

    11th World Conference on Transport Research   Vol. -   2007.6

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  213. The Performance-oriented Highway Planning and Design Concept and Its Issues

      Vol. No.35   page: 4ページ,CD-ROM   2007.6

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  214. Hierarchical Road Network - Modeling for Planning and Desig

      Vol. No.35   page: 4ページ,CD-ROM   2007.6

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  215. A Proposal on Speed-Flow Curves for Intercity Highway Sections

      Vol. No.35   page: 4ページ,CD-ROM   2007.6

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  216. Estimating Desired Speeds in Japan Two-lane Highways

    Catbagan, L. J. and Nakamura, H.

      Vol. No.35   page: 4ページ,CD-ROM   2007.6

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  217. Needs for the Image Processing Technique as a Convenient Traffic Flow Analysis Tool and its Practical Issues

      Vol. Vol.42, No.3   page: 20-27   2007.5

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  218. Characteristics of Breakdown Phenomena in Japan Urban Expressway Merging Sections

    Shawky, M. and Nakamura, H

    86th TRB Annual Meeting     page: 10 pages, CD-ROM   2007.1

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  219. Signalized Intersection Design and Operations: Experiences in Germany and Japan

    Tang, K and Nakamura, H.

    7th International Conference of Chinese Transportation Professionals   Vol. Shanghai   2007

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  220. Characteristics of breakdown phenomenon in merging sections of urban expressways in Japan

    Shawky, M; Nakamura, H

    TRANSPORTATION RESEARCH RECORD   ( 2012 ) page: 11 - 19   2007

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    Language:Japanese   Publisher:Transportation Research Record  

    This paper aims to investigate the breakdown phenomenon at on-ramp merging sections of urban expressways in Japan. The breakdown events are treated here as a probabilistic phenomenon. Six merging sections at which breakdowns frequently occur are selected to be different in their geometry in relation to acceleration lane length and ramp entrance side. Three different aspects of merging capacity are recognized: the maximum outflow rate before the breakdown, the outflow rate when the breakdown starts to occur, and the outflow rates during the queue discharge period. These outflow aspects are analyzed after they are converted into an equivalent passenger car unit to eliminate the effect of heavy vehicles. Then the probability of breakdown at these sections is investigated as a function of outflow rates. The observed breakdown probabilities follow the Weibull distribution function at all sections, with close values of shape parameter and wide range values of scale parameter. The values of the scale parameter are used to investigate the effects of the acceleration lane length and entrance ramp side. Moreover, the breakdown probability is investigated as a function of the occupancy observed immediately downstream of the merging section. Last, the effects of ramp flow ratio and interval length of aggregated data are discussed.

    DOI: 10.3141/2012-02

    Web of Science

    Scopus

  221. A Comparative Study on Traffic Characteristics and Driver Behavior at Signalized Intersections in Germany and Japan

    Tang Keshuang, Nakamura Hideki

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2007 ( 0 ) page: 324 - 324   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    The authors are currently investigating the applicability of the operation policy, commonly applied at signalized intersections in Germany, for Japanese signalized intersections. As an initial step, this study analyzed traffic characteristics and driver behavior at several typical German and Japanese intersections to understand the impacts of such policy on them. The results showed that German intersections had significantly lower starting response time (SRT) and start-up lost time (SULT), which was due to the sequence of signal indications. However, no apparent variations existed in saturation flow rate (SFR) and lost time in amber (LTA). Left turners at German intersections tended to be more aggressive in choosing suitable gaps, indicated by critical gap and 1/PET values. Moreover, longer all-red clearance interval and gap adaptive control seemed to encourage aggressive pass. Lower stop-line crossing during amber (SCA) and red light violation (RLV) rates at German intersections were attributed to multiple factors.

    DOI: 10.11175/eastpro.2007.0.324.0

    CiNii Research

  222. A COMPARATIVE STUDY ON TRAFFIC CHARACTERISTICS AND DRIVER BEHAVIOR AT SIGNALIZED INTERSECTIONS IN GERMANY AND JAPAN

    TANG Keshuang, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 7 ( 0 ) page: 2470 - 2485   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    The authors are currently investigating the applicability of the operation policy, commonly applied at signalized intersections in Germany, for Japanese signalized intersections. As an initial step, this study analyzed traffic characteristics and driver behavior at several typical German and Japanese intersections to understand the impacts of such policy on them. The results showed that German intersections had significantly lower starting response time (SRT) and start-up lost time (SULT), which was due to the sequence of signal indications. However, no apparent variations existed in saturation flow rate (SFR) and lost time in amber (LTA). Left turners at German intersections tended to be more aggressive in choosing suitable gaps, indicated by critical gap and 1/PET values. Moreover, longer all-red clearance interval and gap adaptive control seemed to encourage aggressive pass. Lower stop-line crossing during amber (SCA) and red light violation (RLV) rates at German intersections were attributed to multiple factors.

    DOI: 10.11175/easts.7.2470

    CiNii Research

  223. Influence of Heavy Vehicles on Japan Two-Lane Highway Speed and Follower Flow Characteristics

    Catbagan Jerome Lejano, Nakamura Hideki

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2007 ( 0 ) page: 330 - 330   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    The effects of heavy vehicles become more pronounced in two-lane highway facilities with passing restrictions since vehicles in a platoon do not have any other choice but to follow the leaders' choice of speed, which is usually below their desired speed levels. Furthermore, platoon lengths are expected to be longer than usual, affecting level of service indicators such as follower density and average travel speed. This study aims to make a preliminary analysis of the influence of heavy vehicle on such facility types in Japan. Detector data were analyzed for two different time periods - peak and weekday. The speed of heavy vehicles has a direct effect on follower speed and follower density was found to become more sensitive to heavy vehicle percentage as flow rate increases. Average speed was also found to be more sensitive to heavy vehicle presence on upgrades, especially during the evening period.

    DOI: 10.11175/eastpro.2007.0.330.0

    CiNii Research

  224. An Estimation Method of Hourly Traffic Demand Fluctuation throughout a Year for the Performance-oriented Highway Planning and Design

    UTSUMI Taisuke, NAKAMURA Hideki, WATANABE Masamitsu

    INFRASTRUCTURE PLANNING REVIEW   Vol. 24 ( 24 ) page: 825 - 834   2007

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    Publisher:Japan Society of Civil Engineers  

    The authors have been advocating performance-oriented highway planning and design methodology in Japan. For this, it is necessary to estimate the hourly traffic demand fluctuation on a planned highway section throughout a year. This study proposes a method to estimate it within two phases; estimating the daily traffic demand phase and setting the hourly traffic demand coefficient phase, in consideration of potential hourly traffic demand. Estimates for each category, corresponding to road characteristics can be calculated using this method. This procedure enables the performancecheck of any planned highway sections throughout a year by inputting traffic demand into the respective design performance curve.

    DOI: 10.2208/journalip.24.825

    CiNii Research

  225. REPRODUCING THE HOURLY TRAFFIC DEMAND FLUCTUATION THROUGHOUT A YEAR FOR THE EVALUATION OF HIGHWAY CROSS-SECTION DESIGN

    NAKAMURA Hideki, UTSUMI Taisuke, WATANABE Masamitsu

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2007 ( 0 ) page: 277 - 277   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    The authors have advocated a new planning and design methodology in for highways in Japan, which includes operational performance check in consideration of the traffic demand fluctuation. For this method, it is necessary to reproduce the hourly traffic demand fluctuation on a planned and designed highway section throughout a year. This study proposes a method to reproduce it with two phases; reproducing the daily traffic demand phase and setting the hourly traffic demand coefficient phase, in consideration of potential hourly traffic demand on a day with congestion. The reproduced hourly traffic demand fluctuation using this method was validated on two expressway sections in Japan. As a result, we could verify that the reproduction precision was satisfactory except that it could not consider some special local characteristics.

    DOI: 10.11175/eastpro.2007.0.277.0

    CiNii Research

  226. PERFORMANCE EVALUATION OF ROUNDABOUTS CONSIDERING TRAFFIC CONFLICTS

    NAKAMURA Hideki, MABUCHI Taiki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 7 ( 0 ) page: 2412 - 2424   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    A roundabout is an alternative type of junction control that reduces delay under low traffic demand. Conditions under which they are advantageous in terms of capacity and delay have been already shown in existing researches. However, the implementation of roundabouts is likely to be negatively evaluated, particularly in Japan; due to safety reasons since traffic conflicts are inevitable when merging. In this paper, a methodology for the performance evaluation of at-grade junctions considering a trading-off relationship between delay and vehicular conflicts is proposed. The performance of signalized intersections and roundabouts are also compared by applying this methodology. As a result, it was found that roundabouts are still more advantageous than signalized intersections when approaching traffic volume is less than 500 vph, even though not only delay but also conflicts were taken into account as evaluation indices.

    DOI: 10.11175/easts.7.2412

    CiNii Research

  227. PERFORMANCE EVALUATION OF HIGHWAY SEGMENTS USING TRAVEL TIME BASED PERFORMANCE MEASURES

    Mehran Babak, Nakamura Hideki

    Proceedings of the Eastern Asia Society for Transportation Studies   Vol. 2007 ( 0 ) page: 318 - 318   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    This paper introduces some applications of travel time based performance measures and mainly the travel time reliability as a measure of performance. In this research, operational conditions of two different segments of an intercity expressway are evaluated and compared by using travel time based performance measures. While Buffer Time Index and Travel Time Index are used to evaluate travel time reliability and congestion, it is observed that travel times are more reliable during off-peak periods, whereas unreliability dramatically increases during the peak periods. Additionally, travel time reliability varies from time to time according to demand fluctuations and traffic influencing events. Finally, highway segments are found to be more susceptible to disruptions caused by traffic influencing events once congestion starts to build up.

    DOI: 10.11175/eastpro.2007.0.318.0

    CiNii Research

  228. INFLUENCE OF HEAVY VEHICLES ON JAPAN TWO-LANE HIGHWAY SPEED AND FOLLOWER FLOW CHARACTERISTICS

    CATBAGAN Jerome, NAKAMURA Hideki

    Journal of the Eastern Asia Society for Transportation Studies   Vol. 7 ( 0 ) page: 2533 - 2545   2007

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    Language:English   Publisher:Eastern Asia Society for Transportation Studies  

    The effects of heavy vehicles become more pronounced in two-lane highway facilities with passing restrictions since vehicles in a platoon do not have any other choice but to follow the leaders’ choice of speed, which is usually below their desired speed levels. Furthermore, platoon lengths are expected to be longer than usual, affecting level of service indicators such as follower density and average travel speed. This study aims to make a preliminary analysis of the influence of heavy vehicle on such facility types in Japan. Detector data were analyzed for two different time periods — peak and weekday. The speed of heavy vehicles has a direct effect on follower speed and follower density was found to become more sensitive to heavy vehicle percentage as flow rate increases. Average speed was also found to be more sensitive to heavy vehicle presence on upgrades, especially during the evening period.

    DOI: 10.11175/easts.7.2533

    CiNii Research

  229. Effects of Heavy Vehicles on Following Behavior in Two-Lane Highway Sections

    Catbagan, J., Nakamura, H. and Utsumi, T

      Vol. No.34   page: 4ページ,CD-ROM   2006.12

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  230. On-Ramp Merging Capacity in Japan Urban Expressways: A Stochastic Approach

    Shawky, M. and Nakamura, H.

      Vol. No.34   page: 4ページ,CD-ROM   2006.12

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  231. An Investigation on Roundabout Design and Operational Performance

      Vol. No.34   page: 4ページ,CD-ROM   2006.12

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  232. A Study on Quantification of Street Level of Service Regarding Land Access

      Vol. No.34   page: 4ページ,CD-ROM   2006.12

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  233. Evaluation of Performance Measures for Two-Lane Expressways in Japan, Transportation Research Record Reviewed

    Catbagan, L.J. and Nakamura, H.

    Transportation Research Board     page: 111-118   2006.12

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  234. Reproducing Hourly Traffic Demand Fluctuation through a Year

      Vol. No.34   page: 4ページ,CD-ROM   2006.12

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  235. Street Structural Treatments of On-street Parking

      Vol. Vol.41, No.6   page: 40-44   2006.11

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    Authorship:Lead author   Language:Japanese  

  236. TrafficAnalyzer - The Integrated Video Image Processing System for Traffic Flow Analysis

    Suzuki, K. and Nakamura, H.

    13th World Congress on Intelligent Transportation Systems     page: 8 pages in CD-ROM   2006.10

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    Language:English  

  237. Performance Comparison between Roundabouts and Signalized Intersections Considering Vehicular Conflicts Reviewed

    Traffic Engineering   Vol. Vol.41 ( No.5 ) page: 69-79   2006.9

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  238. Lichtsignalsteuerung in Japanraffic Signal Control in Japan Reviewed

    Boltze, M., Kittler, W. and Nakamura, H.

    Strassenverkehrstechnik   Vol. 50 ( Jahrgang ) page: 531-537   2006.9

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  239. An Investigation on Performance Measures for Two-Lane Expressways in Japan

    Catbagan, L.J. and Nakamura, H.

    Proceedings of the 5th International Symposium on Highway Capacity and Quality of Service, Transportation Research Board     page: 209-218   2006.7

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  240. Randomness Nature of Breakdown Phenomena in Japan Urban Expressway Merging Sections

    Shawky, M. and Nakamura, H

    Proceedings of the 8th International Summer Symposium, Japan Society of Civil Engineers     page: 239-242   2006.7

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  241. An Overview on Capacity and Quality of Service Studies in Japan Invited

    Nakamura, H. and Oguchi, T.

    Proceedings of the 5th International Symposium on Highway Capacity and Quality of Service, Transportation Research Board     page: 87-104   2006.7

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  242. Development and Performance Evaluation of a Video Image Processing System for Traffic Flow Analysis- TrafficAnalyzer Reviewed

      Vol. vol.62 ( No.3 ) page: 276-287   2006.7

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  243. 後悔と感心

    中村 英樹

    IATSS review = 国際交通安全学会誌   Vol. 31 ( 1 ) page: 3   2006.6

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    CiNii Research

  244. 道路機能に対応した性能照査型道路設計と交通運用

    中村 英樹

    IATSS review = 国際交通安全学会誌   Vol. 31 ( 1 ) page: 75 - 80   2006.6

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  245. 道路機能に対応した性能照査型道路設計と交通運用

    中村英樹

    IATSS Review   Vol. Vol. 31, No.1   page: 75-80   2006.6

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    Authorship:Lead author   Language:Japanese  

  246. 後悔と感心

    中村英樹

    IATSS Review 論壇   Vol. Vol. 31, No.1   page: 3   2006.6

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  247. Review and Perspective of Highway Capacity and Quality of Service Research in Japan

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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  248. Research Issues for Designing Roundabout Geometry in Japan

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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  249. An Analysis on Traffic Demand Fluctuation Characteristics for the Hierarchical Highway Planning and Design

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  250. A Study on the Various Impacts on Speed-Flow Relationship in Divided TWTL Expressway Sections

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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  251. Practical Issues of Applying Image Processing Technique in the Field of Traffic Engineering

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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  252. Application of the Microsimulator INSPECTOR to a Feasibility Study on Transit Mall

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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  253. A trial argument of planning and design of road network based on time-spatial fluctuation of travel demand

      Vol. No.33   page: 4ページ,CD-ROM   2006.6

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  254. Performance Measure Evaluation for Japan Two-Lane Expressways

    Catbagan, L.J. and Nakamura, H.

    85th TRB Annual Meeting     page: 10 pages, CD-ROM   2006.1

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  255. Evaluation of performance measures for two-lane expressways in Japan

    Catbagan, JL; Nakamura, H

    HIGHWAY CAPACITY AND QUALITY OF SERVICE 2006   ( 1988 ) page: 111 - +   2006

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    Language:Japanese   Publisher:Transportation Research Record  

    Two-lane expressways exist as provisional sections for future expansion to four-lane expressways in Japan, although recently such roadway types have been considered for construction for permanent use. Their highway classification may fall somewhere between common (multilane) expressways and ordinary two-lane highways, with full access control and high speed limits but with only one lane per direction of travel. Since this type of highway is unique, methodologies for service level measurement of other uninterrupted-flow facilities are not applicable. Percent time spent following, for instance, is estimated with significant consideration of the opposing flow rate, which has practically no effect on driving conditions since a median barrier is present in all sections. The goal of this study is to analyze and compare possible performance measures that would best describe the traffic operational characteristics of two-lane expressways. Among the performance measures considered, follower density had much promise, having shown strong relationships with flow rate. Since the available data were only those taken during off-peak periods, further observations of follower flow must be made during congested or near-congested flow to establish follower density and volume relationships for all traffic conditions.

    DOI: 10.3141/1988-16

    Web of Science

    Scopus

  256. DEVELOPMENT AND PERFORMANCE EVALUATION OF A VIDEO IMAGE PROCESSING SYSTEM FOR TRAFFIC FLOW ANALYSIS - TrafficAnalyzer

    SUZUKI Kazufumi, NAKAMURA Hideki

    Doboku Gakkai Ronbunshuu D   Vol. 62 ( 3 ) page: 276 - 287   2006

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    Language:Japanese   Publisher:Japan Society of Civil Engineers  

    In the field of traffic engineering, video image analysis is an essential technique for correct understanding of traffic phenomena and has been often used for many purposes. However, manual use of this type of technique is a very labor-intensive work. In this study, a multi-functional video image processing system is developed, which can 1) count traffic volumes, 2) track moving objects such as vehicles and pedestrians, and 3) recognize license plates automatically by using image processing technology. Case studies are carried out by applying this system to the actual road traffic, and its performance and accuracy are evaluated. In conclusion, the developed system showed sufficiently satisfactory performance for practical use.

    DOI: 10.2208/jscejd.62.276

    CiNii Research

  257. Traffic analyzer - The integrated video image processing system for traffic flow analysis

    Suzuki K., Nakamura H.

    13th World Congress on Intelligent Transport Systems and Services     2006

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    Publisher:13th World Congress on Intelligent Transport Systems and Services  

    This paper presents the overview of an integrated video image processing system which can count traffic volumes, track moving objects such as vehicles and pedestrians, and recognize license plates number automatically by using image processing technology without any special hardware. Case studies are carried out by applying this system to the actual road traffic scene, and its performance and accuracy are evaluated. Experimental results of the image processing show that each analysis function has sufficiently satisfactory performance for practical use.

    Scopus

  258. 路上駐車を考慮した街路構造

    中村 英樹

    交通工学 41-6     page: 40 - 44   2006

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  259. 日本の交通容量・サービスの質に関する研究展望

    中村 英樹, 大口 敬

    土木計画学研究・講演集 33巻(CD-ROM)     2006

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  260. 日本でのラウンドアバウト設計のための調査研究課題

    中村 英樹

    土木計画学研究・講演集 33(CD-ROM)     page: 4   2006

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  261. 往復分離2車線自専道における交通量-速度曲線への影響要因分析

    中村 英樹

    土木計画学研究・講演集 33(CD-ROM)     page: 4   2006

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  262. 交通需要の時空間変動を考慮した新たな道路ネットワーク計画設計試論

    大口 敬, 中村 英樹, 桑原 雅夫

    土木計画学研究・講演集 33巻(CD-ROM)     2006

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  263. 交通需要の時空間変動を考慮した新たな道路ネットワーク計画設計試論

    大口 敬, 中村 英樹, 桑原 雅夫

    土木計画学研究発表会・講演集 第33回(CD-ROM)     2006

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  264. ラウンドアバウトの幾何構造と性能に関する検討

    中村 英樹

    土木計画学研究・講演集 34(CD-ROM)     page: 4   2006

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  265. Quantifying Passing Lane Effects on Two Lane Expressways

    Catbagan, J., Nakamura, H. and Nakanishi, K

      Vol. No.32   page: 3ページ,CD-ROM   2005.12

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  266. At-grade Intersections Analysis by Combining Directional Ratio and Geometric Conditions

      Vol. No.32   page: 4ページ,CD-ROM   2005.12

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  267. Vehicle Merging Behavior Analysis on Urban Expressways Using Video Image Data

      Vol. No.32   page: 4ページ,CD-ROM   2005.12

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  268. Development and Performance Evaluation of a Traffic Counting System Using Video Image Processing Technique Reviewed

        page: 365-370   2005.12

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  269. Detection of Unmapped Road Links by Utilizing Off-Link Probe Data Reviewed

    Wang, R., Nakamura, H. and Izu, N.

    International Journal of ITS Research   Vol. Vol.3   page: 49-57   2005.11

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  270. Parkraumbewirtschaftung – Was macht Japan anders?Parking Space Management: the Japanese Way Reviewed

    Trieb, A., Sch&auml;fer, P., Nakamura, H.

    Internationales Verkehrswesen, 57. Jahrgang, Nr.10     page: 434-437   2005.10

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  271. Performance Analysis of Roundabouts and Signalized Intersections Considering Traffic Conflicts Reviewed

        page: 45-48   2005.10

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  272. A Case Study on Urban Street Geometric Design Considering the Selective Acceptance of On-street Parking Reviewed

        page: 109-112   2005.10

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  273. An Overview on Ramp Metering: Its Performance and Limits

    Shawky, M. and Nakamura, H.

    Proceedings of the 7th International Summer Symposium, Japan Society of Civil Engineers     page: 235-238   2005.7

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  274. Analysis of Two-Lane Expressway Traffic Characteristics

    Catbagan, J. and Nakamura, H.

    Proceedings of the 7th International Summer Symposium, Japan Society of Civil Engineers     page: 239-242   2005.7

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  275. Geometric design of urban streets considering the selective acceptance of on-street parking

      Vol. No.31   page: 4ページ,CD-ROM   2005.6

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  276. A proposal on the hierarchical categories for geometric design of highways and streets corresponding to their functions

      Vol. No.31   page: 4ページ,CD-ROM   2005.6

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  277. A Methodology on Performance Evaluation of Roundabouts Considering Traffic Conflicts

      Vol. No.31   page: 4ページ,CD-ROM   2005.6

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  278. Tips for coordination between road geometric designs and traffic operations

      Vol. No.31   page: 4ページ,CD-ROM   2005.6

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  279. A trial argument of planning and design of road network based on the concept of bottlenecks

      Vol. No.31   page: 4ページ,CD-ROM   2005.6

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  280. 成熟時代に求められる道路技術者の情熱

    中村英樹

    月刊建設   Vol. Vol.49   page: 4-5   2005.4

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  281. Performance of Highway Traffic and Level of Service

      Vol. Vol.40, No.1   page: 7-10   2005.1

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  282. ボトルネックベースで考える道路ネットワーク計画設計試論

    大口 敬, 中村 英樹, 森田 綽之, 桑原 雅夫

    土木計画学研究・講演集 31(CD-ROM)     page: 4   2005

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  283. 機能に対応した道路幾何構造設計のための道路階層区分の試案

    中村 英樹, 大口 敬, 尾崎 晴男

    土木計画学研究・講演集 31(CD-ROM)     page: 4   2005

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  284. 機械に対応した道路幾何構造設計のための道路階層区分の試案

    中村 英樹, 大口 敬, 森田 綽之

    土木計画学研究・講演集 31(CD-ROM)     page: 4   2005

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  285. 今後の道路幾何構造設計と交通運用へのツボ

    尾崎 晴男, 中村 英樹, 大口 敬, 森田 綽之

    土木計画学研究・講演集 31(CD-ROM)     page: 4   2005

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  286. 交差点条件による平面交差部の性能評価

    中村 英樹

    土木計画学研究・講演集 32(CD-ROM)     page: 4   2005

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  287. Performance evaluation technique for roundabouts considering delay and conflicts

      Vol. No.30   page: 4ページ   2004.11

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  288. Evaluation Framework for Impacts of Traffic Signal Parameter Settings and Intersection Geometry on User's Risky Behavior

      Vol. No.30   page: 4ページ   2004.11

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  289. Measurement and Assessment of Highway Quality of Service

    KITA Hideyuki, NAKAMURA Hideki

      ( 772 ) page: 1 - 2   2004.10

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    CiNii Research

  290. Measurement and Assessment of Highway Quality of Service

    KITA Hideyuki, NAKAMURA Hideki

    Doboku Gakkai Ronbunshu   Vol. 2004 ( 772 ) page: 1 - 2   2004.10

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    Publisher:Japan Society of Civil Engineers  

    DOI: 10.2208/jscej.2004.772_1

    CiNii Research

  291. EVALUATION OF LEVEL OF SERVICE IN BASIC EXPRESSWAY SECTIONS BASED ON INDIRECT MEASUREMENT OF DRIVER'S MENTAL STRESS

    NAKAMURA Hideki, SUZUKI Koji, RYU Shunsei

      ( 772 ) page: 11 - 21   2004.10

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  292. Analysis on Driver's Risky Behaviors at Signalized Intersections during Inter-green periods

    Suzuki, K., Nakamura, H., Yamaguchi, S.

    11th World Congress on Intelligent Transportation Systems     page: 8 pages in CD-ROM   2004.10

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  293. Estimation of Urban Street Geometric Characteristics by Using Probe Vehicle Data

    Wang, R., Nakamura, H., Izu, N.

    11th World Congress on Intelligent Transportation Systems     page: 8 pages in CD-ROM   2004.10

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  294. INSPECTOR – The Integrated Network Simulator for Performance Evaluation on Comprehensive Traffic OpeRation

    Nakamura, H., Suzuki, K.

    11th World Congress on Intelligent Transportation Systems     page: 15 pages in CD-ROM   2004.10

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  295. Evaluation of Level of Service in Basic Expressway Sections Based on Indirect Measurement of Driver's Mental Stress Reviewed

      Vol. No.772 ( IV-65 ) page: 11-21   2004.10

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  296. A Study on Impacts of Variable Graphic Signboard on Expressway Traffic Flows Reviewed

        page: 245-250   2004.10

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  297. Development of an Easy-to-Use Multi-function Video Image Processing System Reviewed

        page: 69-72   2004.10

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  298. Application of INSPECTOR to the Evaluation of Park-and-Bus-Ride in the Urban Commercial District Reviewed

        page: 197-200   2004.10

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  299. Analysis on Risky Behaviors at Inter-green Period of Traffic Signal Timings Reviewed

        page: 105-108   2004.10

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  300. Analysis on Driver's and Pedestrian's Perception for the Evaluation of Cycle Length at Under-saturated Signalized Intersections

    Suzuki, K., Nakamura, H., Yamaguchi, S.

    10th World Conference on Transport Research     page: 12 pages in CD-ROM   2004.7

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  301. Development of a Network Traffic Simulator INSPECTOR and its Application to the Evaluation of Parking Charge Control Reviewed

      Vol. Vol.39 ( No.4 ) page: 72-83   2004.7

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  302. Influence of Probe Vehicle Sample Size on Expressway Travel Speed Estimation Reviewed

    Wang, R., Nakamura, H.

    Journal of the 10th WCTR     page: 11 pages in CD-ROM   2004.7

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  303. Issues on highway geometric design making the best use of their performance

      Vol. No.29   page: 4ページ   2004.6

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  304. Road geometric design issues for securing the performance of highways and streets

      Vol. Vol.759   page: 26-31   2004.5

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  305. Behavior Risk Estimation Model for the Evaluation of Cycle Length Based on Driver's Perception at Signalized Intersection

    Suzuki, K., Nakamura, H. and Yamaguchi, S.

    8th International Conference on Applications of Advanced Technologies in Transportation (8th AATT), ASCE     page: 208-212   2004.5

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  306. Error Characteristic Analysis of Probe and Vehicle Detector Data in a Context of Expressway Travel Speed Estimation Combining Detector and Probe Data

    Wang, R. and Nakamura, H.

    8th International Conference on Applications of Advanced Technologies in Transportation (8th AATT), ASCE     page: 6 pages   2004.5

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  307. Performance of Expressway Travel Time Estimation on the Basis of Probe and Detector Data

    Nakamura, H., Wang, R.

    Proceedings of the International Conference on Transportation Systems Planning and Operation, Volume II     page: 759-768   2004.2

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  308. Behavior risk estimation model for the evaluation of cycle length based on driver's perception at signalized intersection

    Suzuki K., Nakamura H., Yamaguchi S.

    Proceedings of the International Conference on Applications of Advanced Technologies in Transportation Engineering     page: 208 - 212   2004

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    This study aims to analyze the mechanism of risky behavior at inter-green periods and to develop a "behavior risk estimation model" which reflects driver's perception for evaluating cycle length under under-saturated traffic conditions. The risky behaviors at the inter-green period are expressed by a disaggregate logit model for each movement (through, right-rum, left-turn) using field survey data. These models are explained by delay and various traffic conflicts, which are influenced by cycle lengths. The estimated parameters of these models quantitatively indicate that longer cycle length induces more risky behaviors at inter-green periods.

    DOI: 10.1061/40730(144)39

    Scopus

  309. Validation of Expressway Travel Time Estimation Methodology Combining Detector and Probe Data Reviewed

        page: 283-288   2003.12

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  310. A Framework for Evaluating Cycle Length of Traffic Signal Control Incorporating Risk Concept

      Vol. No.28   page: 4ページ   2003.11

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  311. An Investigation on Performance of Roundabout Control Based on Traffic Characteristic Analysis

      Vol. No.28   page: 4ページ   2003.11

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  312. Expressway Travel Time Estimation by Using the Combination of Detector and Probe Vehicle Data

    Wang, R. and Nakamura, H.

    proceedings of 10th World Congress on Intelligent Transport Systems     page: 12 pages   2003.11

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  313. Switch from providing high-grade highways to offering rational services

      Vol. Vol.38 増刊号   page: 5-13   2003.10

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  314. Basic Structure and Performance Verification for the Network Traffic Simulator "INSPECTOR" Reviewed

        page: 181-184   2003.10

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  315. Performance Analysis of Roundabouts as an Alternative for Intersection Control in Japan Reviewed

    Manage, S., Nakamura, H. and Suzuki, K.

    Journal of EASTS'03     page: 871-883   2003.10

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  316. Validation of an Improved Method to Estimate Expressway Travel Time by the Combination of Detector and Probe Data Reviewed

    Wang, R., Nakamura, H. and Goto, M.

    Journal of EASTS'03     page: 2003-2014   2003.10

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  317. Screening Methodology of Expressway Probe Data Considering Vehicle Running Profiles

      Vol. No.27   page: 4ページ   2003.6

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  318. インターネットITS アプリケーション検証シミュレータ

    春田 仁・渋谷裕久・堀口良太・赤羽弘和・森川高行・中村英樹・植原啓介

    土木計画学研究・講演集   Vol. No.27   page: 4ページ   2003.6

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  319. Development and Application of a Traffic Simulator for the Assessment of Parking Management Policies

      Vol. No.27   page: 4ページ   2003.6

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  320. Social Needs and User Needs

      Vol. 第46 ( 第3 ) page: 18   2003.3

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  321. Possibility of accuracy improvement in the expressway travel time estimation by a data fusion technique – detector and floating car data

        page: 643-649   2002.12

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  322. Applicability of Emerging Technologies for Traffic Flow Detection to Traffic Signal Control

      Vol. No.26   page: 4 pages in CD-ROM   2002.11

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  323. Model Analysis on the Effects of Providing Traveler Information by City Attribute

      Vol. No.26   page: 4 pages in CD-ROM   2002.11

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  324. Short Term Prediction Works in Traffic Engineering

    Wang, R., Nakamura, H.

    The State-of-the –art, 9th World Congress on Intelligent Transportation Systems     page: 12 pages in CD-ROM   2002.10

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  325. Recent trend on the establishment of integrated traffic and transport management center in German conurbations

      Vol. Vol.5, No.2   page: 56-59   2002.7

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  326. A Traffic Signal Control Algorithm using ITS Sensing

      Vol. No.25   page: 4 pages in CD-ROM   2002.6

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  327. Discussion on the Dynamic Travel Time Estimation Based on Multiple Data Sources - Combining Emerging Data Collection Devices with Conventional Detectors, Traffic and Transportation Studies

    Wang, R., Nakamura, H.

    Proceedings of the Third International Conference on Traffic and Transportation Studies (ICTTS 2002)   Vol. Volume two   page: 1377-1384, ASCE   2002.6

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  328. Traffic Information Services in Germany

      Vol. Vol.37, No.3   page: 35-41   2002.5

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  329. ITSが目指す新しい地域社会

    中村英樹

    プロジェクト・レポート   Vol. No.32   page: 11-14   2002

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  330. Discussion on the dynamic travel time estimation based on multiple data sources - Combining emerging data collection devices with conventional detectors

    Wang, R; Nakamura, H

    TRAFFIC AND TRANSPORTATION STUDIES, VOLS 1 AND 2, PROCEEDINGS     page: 1377 - 1384   2002

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    Web of Science

  331. A Study on Visitor's Destination and Modal Choice Behavior by Change in Accessibility and Mobility in Downtown Commercial Districts

      Vol. No.24(2)   page: 719-722   2001.11

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  332. Statistical Analysis on the Relationship between Traffic Accident Rate and Traffic Flow Condition in Basic Expressway Sections Reviewed

        page: 173-176   2001.10

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  333. Park and Ride Strategy Evaluation System Combining Modal Choice Models with the Microscopic Traffic Simulation Reviewed

      Vol. Vol.18 ( No.5 ) page: 795-801   2001.9

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  334. Estimation of mental stress under the driving circumstances and its application in the consideration of driver's perception, Conference on Advanced Highway Capacity Modeling Techniques and Quality of Service

    Nakamura, H., Suzuki, K., Ryu, S.

    Transportation Research Board     page: 118-127   2001.7

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  335. Evaluation of Capacity and Level of Service Control Measures in Basic Motorway Sections

        page: .231-238   2001.5

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  336. 東海豪雨における道路交通網被害と情報提供に関する調査分析

    中村英樹・加藤博和・安井伸一

    2000年9月東海豪雨災害に関するミニシンポジウム報告書,土木学会水理委員会河川部会     page: 89-94   2001.1

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  337. 東海豪雨における道路交通網被害と情報提供に関する調査分析

    中村英樹・加藤博和・安井伸一

    2000年9月東海豪雨災害に関するミニシンポジウム報告書 土木学会水理委員会河川部会     page: 89-94   2001.1

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  338. Park and Ride Strategy Evaluation System Combining Modal Choice Models with the Microscopic Traffic Simulation

    NAKAMURA Hideki, HIRAMATSU Tatsuhito, UTSUMI Taisuke

    INFRASTRUCTURE PLANNING REVIEW   Vol. 18 ( 18 ) page: 795 - 802   2001

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    For the planning of the park-and-ride (P&R) strategy in urban areas, it is necessary to estimate the P&R demand appropriately corresponding to the conditions of the policy measure, i. e. size, location and charge of the P&R facilities. In addition, traffic flow conditions caused by the change in demand must be also evaluated. In this study, a modal choice model which includes the access mode choice behavior is developed and change in the demand is expressed by that. A microscopic traffic flow simulation model is also developed in order to express the spatial distribution of the traffic flow conditions dynamically. By combining these models and adding the dynamic park-and-ride (DP&R) choice model to that, a P&R strategy evaluation system is structured, which enables to simulate the entire intermodal trip from origin to destination and the traffic flow in the network. Furthermore, applying this system to the eastern part of Nagoya City, effects by the P&R related measures such as settlement of parking facilities and DP&R are discussed.

    DOI: 10.2208/journalip.18.795

    CiNii Research

  339. Evaluation of the Dynamic Park and Ride Strategy Using a Microscopic Traffic Simulation and Modal Choice Model

      Vol. No.23(1)   page: .587-590   2000.11

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  340. Discussion on the Highway Quality of Service and Its Measurement

      Vol. No.23(1)   page: 756-757   2000.11

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  341. Evaluation of the Dynamic Park and Ride Information Strategy Using Microscopic Intermodal Trip and Traffic Simulation

    Nakamura, H., Hiramatsu, T.

    7th World Congress on Intelligent Transportation Systems     page: 8 pages in CD-ROM   2000.11

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  342. Quantification of the Quality of Service in the Basic Motorway Section Based on Drivers' Perception and Analysis of Its Explanatory Factors Reviewed

      Vol. No.17   page: 941-946   2000.9

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  343. An Analysis of the Interrelationship among Traffic Flow Conditions, Driving Behavior, and Degree of Driver's Satisfaction on Rural Motorways Reviewed

    Nakamura, H., Suzuki, K., Ryu, S.

    Transportation Research Board     page: 42-52   2000.6

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  344. 現実的な交通容量からみたAHSの適用性に関する検討

    中村英樹

    運輸政策研究   Vol. Vol.2, No.4   page: 47-48   2000

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  345. Quantification of the Quality of Service in the Basic Motorway Section Based on Driver's Perception and Analysis of Its Explanatory Factors

    NAKAMURA Hideki, KATO Hirokazu, SUZUKI Koji, RYU Shunsei

    INFRASTRUCTURE PLANNING REVIEW   Vol. 17 ( 17 ) page: 941 - 946   2000

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    This study tries to assess the quality of service of a basic motorway section based on the driver's perception, which is one of the noticeable concerns in the discussion on the quality of service. A field driving survey in a rural motorway section is conducted, in order to collect data on driver's degree of satisfaction under various traffic flow conditions. It is fuither analyzed how these measured values of degree of driver's satisfaction relate to the traffic flow conditions and driving behaviors, and the interrelationship among them is quantitatively described. In addition, setting the level of service based on the average satisfaction degree was tried and was compared with the conventional ones. The result suggests that the traffic condition in motorways, which is assumed in the current Japanese planning procedure, may hardly satisfy the drivers.

    DOI: 10.2208/journalip.17.941

    CiNii Research

  346. 活動時間特性を考慮した観光客周遊行動シミュレーション Reviewed

    中村英樹・福岡真紀子

    第19回交通工学研究発表会論文報告集     page: 153-156   1999.12

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  347. ドライバーの感覚に基づいた交通状況評価の計量手法と要因分析 Reviewed

    中村英樹・加藤博和・鈴木弘司・劉 俊晟

    第19回交通工学研究発表会論文報告集     page: 133-136   1999.12

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  348. An Applicability Study on the Dynamic Park and Ride System by A Traffic Simulation Incorporating User Behavior Model

    Nakamura, H., Kato, H., Utsumi, T.

    6th World Congress on Intelligent Transportation Systems     page: 8 pages in CD-ROM   1999.11

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  349. An Evaluation Method of Traffic Flow Conditions Based on Degree of Drivers' Satisfaction on Motorways

      Vol. No.22   page: 885-888   1999.10

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  350. An Examination of Setting Motorway Level of Service Based on the Life Cycle Assessment Reviewed

      Vol. No.16   page: 933-940   1999.9

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  351. An Analysis on Effects of the Dynamic Park & Ride System in Nagoya Applying an SP Model Reviewed

      Vol. No.16   page: 949-954   1999.9

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  352. A Model Analysis on Effects of the Dynamic Park-and-Ride System in Japan, Using Stated Preference Data Reviewed

    Nakamura, H.

    Proceedings for HEUREKA'99, Optimierung in Verkehr und Transport     page: 73-81   1999.3

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  353. 世紀の大改修プロジェクト : 統一ドイツのアウトバーン再生・整備事業

    中村 英樹

    土木学会誌   Vol. 84 ( 1 ) page: 4 - 9   1999.1

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  354. A Parking Management Policy as a Part of the Integrated Urban Transport Strategy

      Vol. Vol.34, No.1   page: 3-8   1999.1

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  355. Rebuild Project in the Century, Renovation and Provision Project of Motorways in the Unified Germany

    Journal of the Japan Society of Civil Engineers   Vol. 第84 ( 第1 ) page: 4-9   1999.1

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  356. An Analysis on Effects of the Dynamic Park & Ride System in Nagoya Applying an SP Model

    NAKAMURA Hideki, KATO Hirokazu, UTSUMI Taisuke, HIRATA Satoru

    INFRASTRUCTURE PLANNING REVIEW   Vol. 16 ( 16 ) page: 949 - 954   1999

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    Publisher:Japan Society of Civil Engineers  

    This paper describes an assessment of effects by introducing the Dynamic Park and Ride (DP&R) system, which is a typical application of the ITS technology to the intermodal travel management A DP&R choice behavior model is developed, using SP data surveyed by authors in the eastern area of Nagoya City and its vicinity.This choice model is incorporated into a traffic simulation and several scenarios on combinations of policy options for the DP&R are examined.Consequently, it was quantitatively found that some policy options related to improvement of services for P&R should be enforced simultaneously, so that the DP&R system may contribute to reduction of car trips.

    DOI: 10.2208/journalip.16.949

    CiNii Research

  357. An Examination of Setting Motorway Level of Service Based on the Life Cycle Assessment

    NAKAMURA Hideki, KATO Hirokazu, RYU Shunsei, MARUTA Hiroshi, FUTAMURA Toru

    INFRASTRUCTURE PLANNING REVIEW   Vol. 16 ( 16 ) page: 933 - 940   1999

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    Publisher:Japan Society of Civil Engineers  

    The highway level of service plays an important role to determine the highway cross-sectional structure. This study aims at setting the level of service based on estimation of the minimal life cycle cost (LCC), under various geographical and traffic demand conditions. The level of service of the alternative cross-sectional structures which achieve the minimal LCC is quantitatively estimated in terms of volume to capacity ratio. As a result, the tendency is found that the higher graded design gives the smaller LCC. It is also shown that the level of service currently applied in Japan is between the values set by the minimal LCC and the minimal extended-life-cycle-CO<SUB>2</SUB> criteria.

    DOI: 10.2208/journalip.16.933

    CiNii Research

  358. A Model Analysis on Effects of the Dynamic Park & Ride System in Nagoya

      Vol. No.21   1998.11

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  359. A Life Cycle Assessment of Cross-sectional Structure of Motorways

      Vol. No.21   page: 649-652   1998.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  360. A Macro-Analysis on the Characteristics of On-Street Parking and its Explanation by Zone

      Vol. No.21   1998.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  361. An International Comparative Study on the Factors for Assessing Number of Lanes on Multilane Highways Reviewed

    Proceedings for 18th Annual Conference on Traffic Engineering Study     page: 157-160   1998.11

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  362. A Model Analysis on Effects of the Dynamic Park-and-Ride System in Japan, Using Stated Preference Data, Reviewed

    Proceedings for 18th Annual Conference on Traffic Engineering Study     page: 177-180   1998.11

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  363. 運輸交通部門におけるCO2削減に向けての施策技術展開

    中村英樹

    土木学会平成10年度全国大会研究討論会6     page: 13-16   1998.10

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  364. Life Cycle Assessment of CO2 Emission from Inter-City Motorways by Road Cross-sectional Structure Reviewed

    Environmental Systems Research   Vol. No.26   page: 261-270   1998.10

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  365. A Goal-Oriented Approach of Policy Making towards Reducing CO2 Emissions from Transport Sector in Japan Reviewed

    Infrastructure Planing Review   Vol. No.15   page: 739-745   1998.9

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  366. Policy Options and its Target Value Setting for Reducing CO2 Emission from Transport Sector

        page: 121-127   1998.7

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  367. インターモーダル交通マネジメント~ドイツの経験と展望

    中村英樹

    季刊MOBILITY   Vol. No.110   page: 119-124   1998.3

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  368. Freizeitverkehr in Japan – ein &Uuml;berblick

    Nakamura, H.

    Internationales Verkehrswesen   Vol. 50, Jahrgang 1+2   page: 28-29   1998

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  369. Life Cycle Assessment of CO2 Emission from Inter-City Motorways by Road Cross-sectional Structure

    Environmental Systems Research     page: 26   1998

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

  370. A Model Analysis on Effects of the Dynamic Park-and-Ride System in Japan, Using Stated Preference Data

    Proceedings for 18th Annual Conference of Traffic Engineering Study     page: 18   1998

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  371. A Goal-Oriented Approach of Policy Making towards Reducing CO2 Emissions from Transport Sector in Japan

    Infrastructure Planing Review     page: 15   1998

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  372. A Goal-Oriented Approach of Policy Making towards Reducing CO<SUB>2</SUB> Emissions from Transport Sector in Japan

    NAKAMURA Hideki, HAYASHI Yoshitsugu, TSUZUKI Keisuke, KATO Hirokazu, MARUTA Hiroshi

    INFRASTRUCTURE PLANNING REVIEW   Vol. 15 ( 15 ) page: 739 - 745   1998

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    Publisher:Japan Society of Civil Engineers  

    Effective measures against the rapid growth in CO2 emission from Japanese transport sector is urgently needed. However, definite target values of the emission due to the transportation activities, how much and in which cities to be cut down, are not shown. This results in difficulty to make a decision of suitable transport policies. This study therefore indicates the goal values of transport options required for realization of reducing CO2 emission, setting its acceptable level in 2010. For the urban passenger transport in paiticular, it is tried to estimate the values by size of city, according to the characteristics of urban transportation activities. Several available options as a suitable transport policy for the each size of city are finally discussed.

    DOI: 10.2208/journalip.15.739

    CiNii Research

  373. Policy Options and its Target Value Setting for Reducing CO<SUB>2</SUB> Emission from Transport Sector

    HAYASHI Yoshitsugu, NAKAMURA Hideki, KATO Hirokazu, MARUTA Hiroshi

    Proceedings of the Symposium on Global Environment   Vol. 6 ( 6 ) page: 121 - 127   1998

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    Publisher:Japan Society of Civil Engineers  

    CO<SUB>2</SUB> emission from transport sector is drastically increasing, and this trend will never change without any appropriate countermeasures against that. Policies relating to reduction of CO<SUB>2</SUB> emission from transport sector are categorized by 1) stage in environmental influence mechanism, and 2) their method. On the other hand, a target value of CO<SUB>2</SUB> emission from Japanese urban passenger transport in 2010 is assumed to be the same level as that in 1990. Its value is estimated by population size of city, considering differences of transport properties and its effects on CO<SUB>2</SUB> reduction. Furthermore, required amount of each policy option for achieving the target value is calculated. Consequently, it is found that 1) no single policy option is effective, even if vehicle fuel consumption efficiency would be drastically improved, that results in necessity of combining various policy options, 2) effective measures in small cities is essential, whose transport activities are strongly dependent on automobiles and that cause about 80% of total CO<SUB>2</SUB> emission from urban passenger transport.

    DOI: 10.2208/proge.6.121

    CiNii Research

  374. Life Cyde Assessment of CO<SUB>2</SUB> Emission from Inter-city Motorways by Road Cross-sectional Structure

    NAKAMURA Hideki, KATO Hirokazu, MARUTA Hiroshi, FUTAMURA Toru

    ENVIRONMENTAL SYSTEMS RESEARCH   Vol. 26 ( 26 ) page: 261 - 270   1998

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    Publisher:Japan Society of Civil Engineers  

    This paper proposes a method for the comprehensive assessment on cross-sectional structures of inter-city motorways in terms of CO<SUB>2</SUB> emission. The index employed in this study is the “Extended Life-cycle CO<SUB>2</SUB> (ELC-CO<SUB>2</SUB>)” emission from highways. This takes into account of not only the CO<SUB>2</SUB> generated by highway construction and maintenance works, but also the CO<SUB>2</SUB> emission by traffic, which varies by highway cross-sectional design. Such traffic flow characteristics as traffic flow variations and/or speed-flow relationship is also investigated, which has not been considered in the conventional studies on LCA. The CO<SUB>2</SUB> emission by highway construction and maintenance works is estimated using “combined method”, for elevated, mounded, and tunnel sections respectively. Furthermore, various cross-sectional structures by several geographical and land-use conditions are assessed, through the calculation of ELC-CO<SUB>2</SUB> from each alternative.

    DOI: 10.2208/proer1988.26.261

    CiNii Research

  375. 運輸起源のCO2排出削減に向けた交通施策の目標設定型アプローチ

    都築啓輔・中村英樹・林 良嗣

    土木計画学研究・講演集   Vol. No.20(2)   page: 145-148   1997.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  376. ドイツにおける観光交通計画への取り組み

    中村英樹

    土木学会土木計画学第8回ワンデーセミナー講演集     page: 30-35   1996.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  377. 交通量変動特性を考慮した車線数決定方法に関する分析 Reviewed

    山田晴利・中村英樹・西川昌宏

    土木技術資料   Vol. 第38 ( 第8 ) page: 26-31   1996.8

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  378. 30年後の環境共生型交通社会の実現に向けて,30年のあゆみ-21世紀への期待

    中村英樹

    (社)交通工学研究会     page: 27-28   1996.5

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    Authorship:Lead author   Language:Japanese  

  379. ドイツに学ぶ豊かさへの意識

    中村英樹

    土木技術資料   Vol. 38-5   page: 9   1996.5

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  380. Zur Enwicklung des Strassenwesens in Japan und in Deutschland Reviewed

        page: 103-112   1996.3

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  381. An Analytical Study on Road Traffic and Transportation Infrastructure in Germany - 5 years after reunification

    Road   Vol. No.659   page: 65-70   1996.1

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    Authorship:Lead author   Language:Japanese  

  382. ドイツの道路横断面構造基準RAS-Q改正の動向

    中村英樹

    交通工学   Vol. Vol.31, No.1   page: 71-76   1996.1

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  383. Zur Entwicklung des Strassenwesens in Japan und in Deutschland

    Strassenverkehrstechnik   Vol. 40 ( 3 ) page: 103-112   1996

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  384. ドイツに見る近距離公共交通活性化のための新しい試み

    中村英樹

    交通工学   Vol. Vol.30, No.3   page: 67-69   1995.5

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  385. 全国観光交通実態調査用いた発生量モデルに関する分析

    山田晴利・中村英樹・西川昌宏

    土木計画学研究・講演集No.17, スペシャルセッション「観光系道路交通施設整備の新たな視点」     page: 1121-1122   1995.1

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  386. Holiday Traffic Activities and Problems on Planning Procedure for Recreational Roads in Japan Reviewed

    Nakamura, H.

    IATSS Research   Vol. Volume 18 ( No.2 ) page: 53-64   1994.12

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  387. 全国観光交通実態調査の概要

    山田晴利・中村英樹・橋口賢治

    交通工学   Vol. Vol.29, No.2   page: 9-18   1994.3

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    Language:Japanese  

  388. 全国観光交通実態調査を用いた発生量モデルの提案 Reviewed

    山田晴利・屋井鉄雄・中村英樹・兵藤哲朗

    交通工学   Vol. Vol.29 ( No.2 ) page: 19-27   1994.3

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  389. 全国観光交通実態調査

    山田晴利・中村英樹・橋口賢治・植村将一

    土木研究所資料   ( 第3270 ) page: 389   1994.2

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    Language:Japanese  

  390. Holiday Traffic Activities and Problems on Planning Procedure for Recreational Roads in Japan

    IATSS Research   Vol. 18 ( 2 ) page: 53-63   1994

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

  391. A Trip Generation Model Using Nationawide Survey for Recreation Trip

    Traffic Engineering   Vol. 29 ( 2 ) page: 19-27   1994

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

  392. 日交通量変動パターンと道路特性の分析

    中村英樹・山田晴利

    土木計画学研究・講演集   Vol. No.16   page: 27-34   1993.12

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  393. 休日交通の現状と道路計画上の課題

    山田晴利・中村英樹

    都市計画第184号, 日本都市計画学会     page: 40-43   1993.10

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    Language:Japanese  

  394. 休日交通特性に配慮した道路計画の必要性 Reviewed

    山田晴利・中村英樹

    土木技術資料   Vol. 第35 ( 10 ) page: 27-33   1993.10

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  395. 休日交通の実態と道路計画上の問題点 Reviewed

    中村英樹

    IATSS Review   Vol. Vol.19 ( No.2 ) page: 94-101   1993.6

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  396. 英国における道路横断面の決定方法

    中村英樹

    高速道路と自動車   Vol. 第36 ( 第7 ) page: 29-36   1993

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  397. 自動車走行台キロの将来推計

    橋口賢治・山田晴利・中村英樹・谷口栄一・安田泰二

    土木計画学研究・講演集   Vol. No.15   page: 739-745   1992.11

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  398. トリップチェーンを分解した休日観光OD推計モデル

    中村英樹・山田晴利・橋口賢治・藤田清二・星野夏樹

    土木計画学研究・講演集   Vol. No.15   page: 197-204   1992.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  399. 休日交通特性と道路計画

    中村英樹

    第49,50回交通工学講習会テキスト,交通工学研究会     page: 223-238   1992.7

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  400. 織り込み区間の交通容量算出シミュレーション・モデル Reviewed

    中村英樹・桑原雅夫・越 正毅

    土木学会論文集   Vol. Ⅳ-16 ( No.440 ) page: 51-59   1992.1

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    Language:Japanese   Publishing type:Research paper (scientific journal)  

  401. A Simulation Model for Estimating Capacity of Weaving Sections

    Proceedings of the Japan Society of Civil Engineers   Vol. (]G0004[)-16 ( 440 ) page: 51-59   1992

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    Authorship:Lead author   Language:English   Publishing type:Research paper (scientific journal)  

  402. A simulation model for the evaluation of weaving capacity, "Highway Capacity and Level of Service" Reviewed

    Nakamura, H., Kuwahara, M., Koshi, M.

    Transportation Research Board, Balkema     page: 259-270   1991.7

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  403. 首都高速織り込み区間での交通流観測と運転挙動解析

    中村英樹・桑原雅夫・鈴木 隆・越 正毅・赤羽弘和

    土木計画学研究・講演集   Vol. No.12   page: 61-67   1989.12

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  404. An Overview on Area Traffic Control Systems

    Koshi, M., and Nakamura, H.

        page: 1-26   1989.5

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    Language:English  

  405. 飽和方形波モデルによる車群分割・二信号交差点連続停止と交通信号オフセットの関連解析

    中村英樹・越 正毅

    土木計画学研究・講演集   Vol. No.11   page: 291-298   1988.11

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    Authorship:Lead author   Language:Japanese   Publishing type:Research paper (scientific journal)  

  406. 車群分割および二信号交差点連続停止を評価基準とする交通信号オフセット Reviewed

    中村英樹・越 正毅

    生産研究   Vol. 第40 ( 8 ) page: 395-398   1988.8

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Books 18

  1. Global Practices on Road Traffic Signal Control : Fixed-Time Control at Isolated Intersections

    Tang, K., Boltze, M., Nakamura, H. and Tian, Z.( Role: Joint author)

    Elsevier  2019.5  ( ISBN:9780128153024

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    Total pages:344   Language:English Book type:Scholarly book

    Global Practices on Road Traffic Signal Control is a valuable reference on the current state-of-the-art of road traffic signal control around the world. The book provides a detailed description of the common principles of road traffic signal control using a well-defined and consistent format that examines their application in countries and regions across the globe. This important resource considers the differences and special considerations across countries, providing useful insights into selecting control strategies for signal timing at intersections and pedestrian crosswalks. The book's authors also include success stories for coping with increasing traffic-related problems, examining both constraints and the reasons behind them.

    Other Link: https://www.amazon.co.jp/Global-Practices-Traffic-Signal-Control-ebook/dp/B07RK2KG1P

  2. Global practices on road traffic signal control: Fixed-time control at isolated intersections

    Tang K., Boltze M., Nakamura H., Tian Z.( Role: Sole author)

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  2019.1  ( ISBN:9780128153031

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    Language:Japanese

    Global Practices on Road Traffic Signal Control is a valuable reference on the current state-of-the-art of road traffic signal control around the world. The book provides a detailed description of the common principles of road traffic signal control using a well-defined and consistent format that examines their application in countries and regions across the globe. This important resource considers the differences and special considerations across countries, providing useful insights into selecting control strategies for signal timing at intersections and pedestrian crosswalks. The book’s authors also include success stories for coping with increasing traffic-related problems, examining both constraints and the reasons behind them.

    DOI: 10.1016/C2017-0-02878-1

    Scopus

  3. Principles of road traffic signal control

    Boltze M., Nakamura H., Tian Z.( Role: Sole author)

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  2019.1  ( ISBN:9780128153031

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    Language:Japanese

    This chapter elaborates on the major principles of road traffic signal control which do not depend on national regulations. In the first part, the basic functionality of traffic signals is explained, including areas of application, signals and signal heads, signal program elements, and traffic signal control methods. Thereby, major terms used in the context of traffic signal control are explained. The second part summarizes the various impacts which traffic signals have on different road-user groups, and gives advice on a multicriteria and multimodal impact assessment. Section 2.3 briefly explains how to utilize traffic signals for a situation-responsive prioritization of public transport vehicles, for situations with critical air pollution levels, and for situations with special demand for noise protection. Finally, the fourth section introduces the concept of quality management for traffic signals and presents some basic principles of such quality management for the stages of planning, implementation, and operation.

    DOI: 10.1016/B978-0-12-815302-4.00002-9

    Scopus

  4. Japan

    Nakamura H., Iryo-Asano M., Oguchi T.( Role: Sole author)

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  2019.1  ( ISBN:9780128153031

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    Language:Japanese

    This chapter summarizes the basic concept and procedure of traffic signal control in Japan, including not only the current practical settings but also the ideas proposed in the forthcoming Japanese manual. In Section 10.1, a historical overview as well as the current statistics of traffic signal installations are provided. Section 10.2 explains the criteria for how to choose the intersection control type and the quantitative strategy for determining the installation of traffic signals is introduced. Basic ideas of adaptive signal control using time occupancy data are also shown. Regarding the signal phasing plan as in Section 10.4, movement-based control is rarely applied and simple two-phase plans or four-phase plans with permissive-protected right-turn phase (in left-hand traffic) are widely applied conventionally. The detailed calculation method of variables recommended in the Japanese manuals is given in Section 10.5. Although in-depth considerations are proposed in the manual, more simplified methods are applied in practice to obtain several variables, such as settings of intergreen time and minimum pedestrian crossing time. The calculation example in Section 10.7 provides practical approaches with these simple settings to demonstrate the actual conditions in Japan.

    DOI: 10.1016/B978-0-12-815302-4.00010-8

    Scopus

  5. Introduction

    Tang K., Tian Z., Boltze M., Nakamura H.( Role: Sole author)

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  2019.1  ( ISBN:9780128153031

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    Language:Japanese

    This chapter briefly introduces the motivation, scope, purpose, and structure of this book. Section 1.1 outlines the motivation for editing this book and for choosing road traffic signal control as the topic. Section 1.2 introduces the scope of the book, that is, fixed-time control at isolated intersections. Section 1.3 explains potential applications and audiences of the book. Section 1.4 highlights the book structure as well as major contents of each chapter of the book, together with the author information. Finally, Section 1.5 gives some explanations on national differences in notations and terminology.

    DOI: 10.1016/B978-0-12-815302-4.00001-7

    Scopus

  6. Initial comparative analysis of international practice in road traffic signal control

    Tang K., Boltze M., Tian Z., Nakamura H.( Role: Sole author)

    Global Practices on Road Traffic Signal Control: Fixed-Time Control at Isolated Intersections  2019.1  ( ISBN:9780128153031

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    Language:Japanese

    This chapter provides an initial comparative analysis of the state of the practice on fixed-time and isolated signal control in selected countries, based on previous chapters and existing guidelines. The compared items include the number of traffic signals, signal control modes, types of signal controllers and systems, signal displays, signal warrants, stage structure and sequence, some critical signal timing parameters, signal timing procedures, and performance evaluation. Major preliminary findings from the analysis are presented at the end of the chapter. The information presented in the chapter is based on the best knowledge of the authors with the intention of raising greater awareness and exchanging knowledge of traffic signal control from a global perspective. It is not intended, however, to serve as any standards or guidelines for general practice.

    DOI: 10.1016/B978-0-12-815302-4.00015-7

    Scopus

  7. 交通運用状態を考慮した道路計画設計のための交通容量とサービス水準に関する研究

    中村 英樹( Role: Sole author)

    [出版者不明]  2008 

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    Language:Japanese

    CiNii Books

  8. 合理的な道路幾何構造設計と交通運用実態に関する海外学術調査

    中村 英樹( Role: Sole author)

    [出版者不明]  2007 

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    Language:Japanese

    CiNii Books

  9. Technical papers

    Nakamura Hideki, Takashi Oguchi( Role: Sole author)

    Japan Society of Traffic Engineers  2006  ( ISBN:9784905990611

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    Language:English

    CiNii Books

  10. Country reports and special session papers

    Nakamura Hideki, Takashi Oguchi( Role: Sole author)

    Japan society of Traffic Engineers  2006  ( ISBN:9784905990604

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    CiNii Books

  11. 高速道路のサービス水準の計量とその評価手法に関する研究

    中村 英樹( Role: Sole author)

    [出版者不明]  2004 

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    Language:Japanese

    CiNii Books

  12. 都市間道路のサービス水準と幾何構造の評価に関する研究

    中村 英樹( Role: Sole author)

    [出版者不明]  1999 

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    Language:Japanese

    CiNii Books

  13. Roundabout Manual

    Japane Society of Traffic Engineers  2016.4  ( ISBN:9784905990857

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    Language:Japanese Book type:Scholarly book

  14. 交通工学ハンドブック2008

    ( Role: Joint author)

    (社)交通工学研究会  2008 

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    Language:Japanese

  15. Proceedings of the 5th International Symposium on Highway Capacity and Quality of Service

    Nakamura, H. and Oguchi, T. ed.( Role: Joint author)

    Transportation Research Board  2006.7 

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    Language:English

  16. A Model Analysis on Effects of the Dynamic Park and Ride System in Japan, Using Stated Preference Data

    HEUREKA '99, Optimierung in Verkehr und Transport  1999 

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    Language:English

  17. 観光交通の特性,観光地交通計画の提案『魅力ある観光地と交通』

    中村英樹/森地・伊東・毛塚(編)( Role: Joint author)

    技報堂出版  1998.6 

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    Language:Japanese

  18. A simulation Model for the Evaluation of Weaving Capacity

    Highway Capacity and Level of Service, A. A. BALKEMA  1991 

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    Language:English

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Presentations 3

  1. A study on appropriate road spacing for the functionally hierarchical network planning

    Goto A.

    Transportation Research Procedia 

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    Event date: 2017

    Language:English   Presentation type:Oral presentation (general)  

    DOI: 10.1016/j.trpro.2017.05.266

    Scopus

  2. An Analysis of Characteristics of Heavy Vehicle Behavior at Roundabouts in Japan

    Kang N.

    Transportation Research Procedia 

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    Event date: 2017

    Language:English   Presentation type:Oral presentation (general)  

    DOI: 10.1016/j.trpro.2017.05.176

    Scopus

  3. Verkehrssituation und Telematikeinsatz im Gro&szlig;raum Nagoya International conference

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    Event date: 2002

KAKENHI (Grants-in-Aid for Scientific Research) 17

  1. Research on safe and efficient control method for intersections depending on characteristics of autonomous vehicles and penetration rates

    Grant number:19H02261  2019.4 - 2022.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Nakamura Hideki

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    Authorship:Principal investigator 

    Grant amount:\17160000 ( Direct Cost: \13200000 、 Indirect Cost:\3960000 )

    A microscopic traffic simulator that reproduces HDV and AV behavior at signalized intersections was developed. By using this simulator, mixed AV traffic flows under various scenarios were reproduced and their effects on safety and capacity were analyzed. For AV, three types of aAV, nAV, and dAV with different behavior characteristics were assumed. Although it is possible to increase the capacity by setting various parameters of AV, it was quantitatively shown that the index value related to the safety evaluation tends to shift to the dangerous side at that time. If the current traffic flow level of HDV only is maintained, the dAV rate is 100%, the safety evaluation index is improved by 30.6%, and if the safety is maintained at the same level as the current level, it was shown that aAV improves capacity by about 37%.

  2. Research on vehicle behaviors and performance evaluation according to the roundabout geometry

    Grant number:16H04426  2016.4 - 2019.3

    NAKAMURA HIDEKI

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    Authorship:Principal investigator 

    Grant amount:\18850000 ( Direct Cost: \14500000 、 Indirect Cost:\4350000 )

    The objective of this research is to develop an estimation method of entry capacity, vehicle trajectories and speeds according to the geometry of roundabout, and to propose a performance evaluation method related to safety and efficiency at the design stage. As a result of estimating the entry capacity and PCE according to the geometric element by using the entry capacity estimation formula and a micro traffic simulator, it was found that the entry capacity changes with the geometric element and the inscribed circle diameter and the entry width of the roundabout significantly affects it. As a safety performance evaluation index, a risk index was proposed, which is represented by the product of the oversight probability that indicates the likelihood of an accident and the collision intensity that indicates the severity of the accident. Then, its modeling was performed to calculate the risk index from any geometric conditions.

  3. Application of visual illusion effects to traffic system.

    Grant number:26242003  2014.4 - 2018.3

    HOSHIKA Tamio

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    Authorship:Coinvestigator(s) 

    This research aims at the development of a new type image hump utilizing the illusion effect.The research team is a member organization that combines psychology, traffic engineering, landscape design research fields. In this research, research and development, construction, and running experiment verification of three types of image humps were carried out. On the other hand, research and development as a speed control system in the bicycle path was also conducted, construction and running experiment verification were carried out. These research results will be utilized as a roundabout transportation system to be introduced in the future. We also believe that symbol signs and guidance sign systems within roundabout circles will be utilized as well.

  4. A study on roundabout performance evaluation considering pedestrians

    Grant number:25289163  2013.4 - 2016.3

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Nakamura Hideki, ASANO MIHO, SUZUKI KOJI

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    Authorship:Principal investigator 

    Grant amount:\15470000 ( Direct Cost: \11900000 、 Indirect Cost:\3570000 )

    This study aims at developing a methodology for entry capacity estimation of roundabouts in Japan considering conflicts between pedestrians and vehicles. Simulation analyses were carried out with respect to impacts of geometry and user behavior conditions that are typical in Japan on entry capacity, and by using their results a multiple regression model for entry capacity estimation was developed. The model was validated with data observed at Roppontsuji roundabout in Karuizawa, Nagano. It was found that the estimation performance of the proposed model was very satisfactory while the existing methodology overestimates the capacity.

  5. Safety assessment of signalized intersections through modeling pedestrian-vehicle conflicts

    Grant number:22360205  2010 - 2012

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    NAKAMURA Hideki, ASANO Miho, OGUCHI Takashi, HAMAOKA Hidekatsu

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    Authorship:Principal investigator 

    Grant amount:\13390000 ( Direct Cost: \10300000 、 Indirect Cost:\3090000 )

    This study aims at developing a methodology for safety assessment of signalized intersections by focusing on the conflict between pedestrians and vehicles. Based on the field data collected by video cameras at a number of signalized intersections, vehicle and pedestrianbehavioral models have been established, which can reasonably represent user speeds, trajectories andtheir interactions under various layouts and operations of signalized intersections. The proposed methodology enables to evaluate the effects of improvements in the geometric layouts and operations of signalized intersections on the safety performance prior to implementation.

  6. Land-use and transport strategy for avoiding global environmental load and mobility divide

    Grant number:20310024  2008 - 2010

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    HAYASHI Yoshitsugu, NAKAMURA Hideki, KATO Hirokazu

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    Authorship:Coinvestigator(s) 

    This study aims to examine the "mobility divide" (gaps in mobility level among socio-economic classes) in the mega-cities. First a survey on citizens' perception on mobility is conducted and difference between income classes is clear. These analyses Result in severe mobility divide and motorization problems and draw attention to urgent urban policy making and further suggest the provision of public transport mode for poors.

  7. Integrated design of geometric planning and traffic controls of intersections

    Grant number:18360248  2006 - 2008

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    OZAKI Haruo, NAKAMURA Hideki, OGUCHI Takashi

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    Authorship:Coinvestigator(s) 

  8. Highway Planning and Design based on Hierarchical Network Structure

    Grant number:18206055  2006 - 2008

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (A)

    KUWAHARA Masao, MORITA Hirohisa, OZAKI Haruo, NAKAMURA Hideki, OGUCHI Takashi, HAMAOKA Hidekatsu, TANAKA Shinji

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    Authorship:Coinvestigator(s) 

  9. A Study on Highway Capacity and Level of Service for Geometric Design Considering Traffic Operational Conditions

    Grant number:17360245  2005 - 2007

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    NAKAMURA Hideki, OGUCHI Takashi, MORITA Hirohisa

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    Authorship:Principal investigator 

    Grant amount:\10010000 ( Direct Cost: \9200000 、 Indirect Cost:\810000 )

    (1) Analysis on the level of service on multilane highways and its influencing factors.
    Realized speeds and capacities under various geometric and traffic flow conditions were investigated and geometric, influencing factors to them were extensively analyzed. By using vehicle detector data on intercity, urban expressways and highways, speed-flow relationships were identified corresponding to such various conditions as gradient, heavy vehicle ratio and weather conditions.
    (2) Analysis on the measure of effectiveness on two-way two-lane highways.
    The follower density was found to be most suitable measure of effectiveness for two-lane highways where passing behavior is difficult to be performed. In order to appropriately estimate the follower density, judgment criteria of the follower condition were investigated by using raw pulse data of vehicle detectors. A methodology to probabilistically identify followers by using both of headway and speed of individual vehicles were proposed. This methodology can identify followers more reasonable than a conventional methodology which uses a fixed headway value only as a threshold.
    (3) Analysis on level of service on arterial streets
    An estimation model for delays caused by stops at signalized intersections was developed, in order to estimate travel speeds of arterial street sections which includes several signalized intersections on a planning stage. This model considers such parameters as demand ratios at entries of intersections, traffic, signal coordinations and cycle lengths, which can roughly be assumed at the planning stage. This model was validated at three arterial sections and found to be reliable enough for the purpose of performance check at the planning stage of arterial streets.

  10. 交通運用と調和した都市部における新たな道路計画・設計論の構築

    Grant number:17656165  2005 - 2006

    科学研究費助成事業  萌芽研究

    大口 敬, 小根山 裕之, 桑原 雅夫, 中村 英樹

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    Authorship:Coinvestigator(s) 

    現在の考え方では,需要の実態を調査し需要予測モデルに基づいて計画し,それを受けて道路幾何構造を設計する,それでも対応しきれない部分を交通運用・管理対策に任せる,という「需要追随型・一方通行型」の計画・設計論である.しかし都市部においては交通需要は潜在化しており,このような考え方は論理的に破綻しており実態に合わない.また近年の公共投資抑制・社会資本の有効活用の方向性も加味すると,抜本的な新たな計画・設計の思想が必要とされている.本研究は,都市部における道路ネットワークの交通容量性能により顕在化する交通需要が制約される条件を明示的に考慮し,また道路幾何構造設計上の制約条件,交通運用・管理対策による交通性能の変動範囲を計画論の中に明示的に反映させ,道路ネットワーク全体を有効に機能させるために求められる計画・設計上の条件を理論・実証の両面から検討し,計画・設計論を構築・提案することを目的とする.
    交通運用性能を規定する交通容量の道路ネットワーク上における空間変動は,合流部・交差点部,その他交通容量上のボトルネックの発生要因となる道路幾何構造条件,および,車線運用,信号制御などの交通運用・制御により制約されて定まる.こうしたネットワーク上の交通容量の解析・評価手法について検討し,新しいネットワーク計画・制約の考え方を提案した.また,ボトルネックの実際の事例として,特に今後わが国における都市部で重要となると考えられる往復2車線分離道路の交通容量の現地実態調査を行い,およびその特性を分析した.

  11. A Survey on the State of the Art on Rational Road Geometric Design and Traffic Operations in Overseas Countries

    Grant number:17404010  2005 - 2006

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    NAKAMURA Hideki, OZAKI Haruo, OGUCHI Takashi

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    Authorship:Principal investigator 

    Grant amount:\13100000 ( Direct Cost: \13100000 )

    As is often the case with some developed overseas countries, careful considerations should be given to details of road geometric design and traffic operations, in order to secure rational functions of road sections corresponding to their hierarchical categories. This study aims at collecting information and data regarding the issues mentioned above in some overseas countries, in order to investigate some improvements on road geometric design and traffic operation in Japan. By visiting universities and administration offices, interviews to several researchers and experts were performed, and related guidelines, manuals, research reports and practical project reports were obtained. Furthermore, traffic flow surveys through video recordings were conducted at four typical signalized intersections (3 in Germany and 1 in UK) and nine roundabouts (5 in Germany, 2 in US and 2 in Australia). These data were analyzed from a viewpoint of user behavior considering their geometric and operational features.

  12. 道路交通サービスの質の評価に関する国際共同研究の企画調査

    Grant number:14605016  2002

    科学研究費助成事業  基盤研究(C)

    喜多 秀行, 中村 英樹, 横松 宗太, 谷本 圭志, 宇野 伸宏, 清水 哲夫

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    Authorship:Coinvestigator(s) 

    「交通の質」に関する議論はこれまであまり明示的に行われておらず,交通密度等それと比較的高い相関性を有すると考えられる交通状態変数により「サービス水準」として便宜的な区分がなされていた程度である.しかし,「交通の質」を道路交通の計画・運用の評価指標として明示的に取り扱うべきとする要請の高まりと新しい分析技術の開発により,新たな展開の可能性が開かれつつあり,国際的な共同研究を実施し交通サービスの質に対する利用者の認識・評価を的確に把握する方法論を確立しようとする気運が高まってきた.そこで,本研究ではその基礎となる研究フレームを構築すべく,8名の国内研究者および独,米,加の6名の海外共同研究者で企画調査を行った.
    具体的には,まず各国における交通容量マニュアルのベースとなっている考え方を抽出して国内外における「交通の質」の評価に関する"社会的要請"とその背後にある状況を列挙・整理し,検討対象の明確化を図るとともに,既往研究のレビューを行い,研究課題に関する現時点における研究の到達範囲を整理した.これと並行して,研究組織を構成する研究者(代表者,分担者,海外研究協力者)の研究アプローチと対象領域を整理し,現時点における研究の欠落領域と重点的に取り組むべき領域を明らかにした.次いで,交通の質を規定するとして採用されている評価指標とその支配要因ならびにモデル構造を比較検討し,定量分析の基礎となる行動実態観測および意識データを統一的な観点から体系的に収集するため,既往研究等を参考にして調査項目や測定尺度,調査手法等を規定する共通の調査フレームを構築した.以上を基に,主として日本側研究者が取り組んできた「行動分析に基づく効用アプローチ」と,独・米・加の研究者による「意識調査に基づく統計アプローチ」を有機的に組み合わせた研究フレームを構築することができた.

  13. A STUDY ON MEASUREMENT AND ASSESSMENT OF THE EXPRESSWAY LEVEL OF SERVICE

    Grant number:12650529  2000 - 2002

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    NAKAMURA Hideki, KATO Hirokazu

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    Authorship:Principal investigator 

    Grant amount:\3200000 ( Direct Cost: \3200000 )

    This study discusses evaluation of quality of service (QOS) of traffic flow, which is one of the major concerns for highway planning and traffic management, from the aspect of driver's perception or comfort. It is shown that the driving comfort can indirectly be measured as driver's mental stress, through modeling the lane-changing behavior. Based on data obtained from a driving survey, several models for vehicular movement in basic expressway sections are estimated, and a traffic simulation model incorporating these models is developed. From the simulation results for various traffic flow levels under unconstrained flow conditions, a relationship between level of service and driver's comfort is shown.

  14. Development of constructing methodology of time-axis program for transport improvement, and environmental load management in Asian developing countries

    Grant number:09450192  1997 - 1999

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    HAYASHI Yoshitsugu, OKUDA Takaaki, NAKAMURA Hideki, MORIKAWA Takayuki, KATO Hirokazu

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    Most mega cities in developing countries are suffering from various urban problems caused by the shortage of social overhead capital to catch up with the rapid economic growth. This research is aimed to construct a methodology that analyzes the urban/global environmentally friendly transportation improvement strategies of avoiding the bottleneck in the urban development.
    Targeting the mega cities in developed countries, which those in developing countries will follow in the future, the mechanism of motorization progress that is encouraged by the economic development and the change in needs of transport infrastructure is clarified. Institutions of transport. infrastructure improvement are surveyed and compared internationally. A mathematical model is constructed to estimate the change in the car ownership and to simulate transport demand, road traffic condition, energy consumption, and environmental load. Consequently, the following mechanism is found : In developing countries, financial systems about the transport infrastructure improvement are insufficient, and urban railway and tram are very poor inside & near mega cities. Under such conditions, if rapid motorization and population concentration were caused, transport, condition would also worsen rapidly. For avoidance of this kind crisis, it is thought to be efficient to establish a financial system to improve transport infrastructure corresponding to the urban development. Especially, the money gained in the land and car market, where demand increases due to the urban development, may be taxed and then transferred to transport improvement.
    As a technique examining detailed transport infrastructure improvement policies in the mega cities of the developing countries, a model to estimate the change in transport conditions due to the provision is constructed. Stated preference survey data on the spot are also used in the modeling. The transport mode choice model is calibrated to forecast, modal-shift, in the case of future railway improvement. And it is also possible to estimate the relationship among conditions of the railway network formation, the service level, and the condition of usage.

  15. 都市間道路のサービス水準と幾何構造の評価に関する研究

    Grant number:09650580  1997 - 1998

    科学研究費助成事業  基盤研究(C)

    中村 英樹, 加藤 博和, 林 良嗣

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    Authorship:Principal investigator 

    Grant amount:\3000000 ( Direct Cost: \3000000 )

    本研究ではまず,日・米・独の各国を対象として,多車線道路の単路部における車線数決定方法,およびそれに関わる影響要因についての比較分析を通して,車線数決定に際して重要な位置を占めるサービスの質にかかわる考え方とその設定値について,わが国の水準は国際的にどの程度であるのかを明らかにした.
    次に,総費用,環境負荷の観点からの道路横断面構成の評価手法を用いて,総費用・環境負荷最小となる道路横断面構成とそのときのサービス水準について検討を行った.費用には,管理者費用として建設費用・維持管理費用を,利用者費用として時間費用・走行費用を計上し,これらを建設段階から供用後40年間の経年合計で積み上げて評価している.また,環境負荷としては,CO_2排出量にライフサイクルアセスメントの考え方を適用し,建設による排出と,維持管理および走行による排出を道路構造別に評価の対象としている.本手法を適用して算出した地形条件別の最適横断面と,既往の手法による決定横断面およびサービス水準について比較考察を行った.
    また,高速道路単路部の様々な交通量レベルにおける,ドライバー満足度や運転挙動の分析を通して,交通状況の具体的評価とドライバーの観点からの道路のサービス水準の設定を試みた.運転挙動データは,走行実験により収集し,これと同時にドライバーへのアンケート調査を行うことによりドライバーの交通状況への感覚を把握した.そして,これらの結果と車両感知器等から得られるマクロな交通特性データを,交通量レベルに応じて明示することが可能となった.さらに,これらの視点を生かしたサービス水準の設定を提案した.

  16. 日本の車検制度が環境や経済に及ぼした影響の分析と発展途上国への移転可能性の検討

    Grant number:08650644  1996

    科学研究費助成事業  基盤研究(C)

    オマ-ル オスマン, 奥田 隆明, 中村 英樹, 林 良嗣

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    Authorship:Coinvestigator(s) 

    本研究では、日本では従来より実施されてきた車検制度が、自動車の大気汚染物質排出を抑制する効果の分析手法を開発するとともに、その効果の事後的分析への適用をはかった。さらにその結果を踏まえ、車検制度を今後の発展途上国での交通公害対策として導入するにあたっての効果および課題について整理を行った。
    車検制度が自動車の大気汚染物質排出抑制に及ぼす効果には、1)代替促進効果:車検費用の賦課によって、車齢の高い車から新車への買い換えを促進させ、低排出車が早く普及する効果、2)車両整備効果:車両の劣化によって排出レベルが基準を上回るようになった車両に対し、整備によって排出レベルを低下させる効果、の2つがある。
    以上の効果を推計するために、まず1)については、車保有者の車両存廃選択行動を、集計ロジット型のモデルにより表現した。説明要因として、各車両の車齢に依存する維持・車検費用と、新車購入費用を組み込んだ。また2)については、運輸省が実施した排出ガス実態調査を利用して、車両の加齢による汚染物質排出量変化を車検制度がある場合とない場合に分けて推計るモデルを構築した。
    以上の計量モデルによる分析例として、日本の全乗用車を対象に車検制度による大気汚染物質削減効果を推計した。その結果、1989年においては、一酸化炭素については23.4%、炭化水素については16.0%、一定の削減効果があることが把握できた。また、両物質ともに、2)車両整備効果による削減が全体の95%以上を占めることも明らかになった。
    一方、発展途上国の車両整備制度に関する調査を行った結果、日本よりかなり緩やかであることが分かった。したがって、日本と同レベルの車検を実施した場合には、その効果は日本以上に得られることが予想される。

  17. A Comparative Study on Integrated Transport Policies as Environmental policies

    Grant number:07455424  1995 - 1996

    Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    HAYASHI Yoshitsugu, TOMITA Yasuo, OKUDA Takaaki, NAKAMURA Hideki

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    Recently, a lot of polices are tackled to reduce global environmental emission from transport sector in Europe. At first, in this study, it is explained what transport policies were introduced in Europe and it is revealed that there are some differences in transport policies and Japan. Secondly, it is considered what transport policies should be tackled in Japan so as to reduce the environmental emission. Thirdly, some environmental and economic models are developed and it is analyzed how these transport polices will be able to reduce global environmental emission in Japan and how they will influence economic activities when they are introduced. Finally, we discuss the evaluation of these transport policies as global environmental polices.

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Teaching Experience (On-campus) 6

  1. First Year Seminar A

    2011

  2. 交通工学特論

    2009

  3. 基礎セミナーA

    2009

  4. 世界の建設プロジェクト

    2009

  5. 社会資本・空間計画学演習

    2009

  6. 交通論

    2009

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Teaching Experience (Off-campus) 1

  1. 1997.4 - 1998.3 中部大学)