The traffic accident in the highway has the large scale damages, not only personal loss but also social loss, because the vehicle is traveling at high speed. In particular, many traffic accidents have occurred on the urban expressway in the merging section where the vehicle is complicated in complex situations. In addition, the number of accidents of elderly people along with the increase of the license prevalence of older drivers are also increasing. In recent years, traffic safety measures encourage the vehicle behavior, such as risk is reduced by providing information boards the presence of a vehicle approaching the driver.
This study aims to analysis of driving behavior when merging support information is provided to the driver. Specifically, we are performed using driving simulator in the urban expressway junction department in a driving simulator. As a result of analysis, a difference was obtained in a speed change by a kind of "merging support device". In addition, the elderly have the differences in the reaction by analysis of variance.

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A massive traffic congestion and urban gridlock has been observed in many places of central Tokyo, when the Great East Japan Earthquake occurred on March 11, 2011. We analyzed the extended process through time and space of the urban gridlock after the earthquake disaster. It is intended to clarify the actual situation of the traffic congestion by the earthquake disaster.
In this study, we analyzed gridlock expansion of central Tokyo using taxi probe data . Furthermore, the gridlock every upbound and downbound traffic lanes were identified. The bottlenecks of high priority for reducing traffic congestion were extracted based on the above analysis.

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The focus of traffic control system of freeway has been slightly shifted from mitigating traffic congestion towards preventing traffic accident during the last decade as the upgrade of the freeway network connection. Due to the intensive effort to investigate the factors relating to the occurrence of traffic accident in the past studies, it has been revealed that the risk of traffic accident gets higher in the critical and congested traffic flow situation. However, the difficulty in collecting the precise and adequate data of traffic flow limits the further understanding of the question; what induces traffic accidents?
To overcome the limitation, this study investigates the applicability of a feedback-based traffic state estimator for the further understanding of the situation inducing traffic accidents. The feedback system is composed of Extended Kalman Filter (EKF) and Cell Transmission Model (CTM), which is extended to represent the influence of road alignment on traffic flow at sag sections. The parameters of a fundamental diagram, which are considered as an indicator of the efficiency of traffic flow, are set as the state variables in EKF. Then, this system is applied to 9 situations where traffic accidents occurred and the variation of the estimated state variables just before and after the traffic accidents is investigated. As a result, it is revealed: (i) the feedback system can estimate rational traffic state where traffic accidents occur, and (ii) in some cases the efficiency of traffic flow tends to deteriorate just before the traffic accidents.

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Traffic fatalities are on the decline for 12 consecutive years in Japan. On the other hand, the percentage of the fatalities in the community streets and the elderly people are increasing. The speed of vehicle at the time of collision is greatly related damage of traffic accidents. In Europe, the ISA (Intelligent Speed Adaptation) system that can control speed properly from the vehicle side in a specific area has been progress in recent years. It is believed that if the verification of the system effects were done properly, the ISA will become innovative measures to guarantee the effectiveness of the speed limit in the community streets of our country. This study aims to determine the acceptability of the elderly driver of the ISA in the streets.

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This paper describes the results of a mobility management (MM) project for leisure travel in Izumotaisha area to promote a stroll. This project consists of three strategies: i) providing brochures with a communication questionnaire, ii) issueing coupons as an incentive of the questionnaire and besides to motivate the respondents to join, and iii) conducting face to face advice in the field, in order to persuade tourists to walk the front approach to the shrine. As a result, tourists who answered the communication questionnaire stayed longer, spent more money and were satisfied more than the other general tourists.

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In this study, we investigated QOS of arterial roads, by using objective data that reflect bicycle users' stress measured by a heart rate monitor and subjective data that represent bicycle users' evaluation of traffic conditions through a questionnaire survey. In order to quantitatively express bicycle users' stress, first, we defined the stress level for bicycle users, and then the factors that have significant impacts on the stress were analyzed by regression model. On the other hand, the questionnaire survey about bicycle users' evaluation on traffic conditions at sidewalks, on road and intersections was conducted. By the covariance structure analysis, the factors largely influencing bicycle users' evaluation were found. Moreover, a methodology for QOS of sidewalks and intersections was proposed, based on the objective and subjective analysis. QOS of the studied arterial roads was quantitatively evaluated, and the effectiveness of traffic policies relating to bicycle users was discussed, through the proposed methodology. Finally, we examined the correlation between objective and subjective data, which confirms the necessity of measuring QOS from both objective and subjective points of view.

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In Japan, the exclusive parking zone system for elderly drivers was introduced in 2010. The concept of this system is the scheme whereby the exclusive parking spaces of the street are reserved for elderly drivers, pregnant women drivers and physically handicapped drivers.
The purpose of this study is to evaluate the effect of this system. In addition, we submit about the problems of elderly people. This paper takes up case studies in Kanagawa Prefecture.

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The Metropolitan expressway, the Hanshin Expressway which is a urban expressway switched over from a uniform toll to a distance based toll in January, 2012. In this study, the pricing based on the distance based toll system assuming the ETC use is examined. The change of level of toll affects the traffic demand. Therefore, the traffic assignment model with variable demand that include the traffic demand estimation is used. In addition, the transit traffic is considered. The stochastic user equilibrium traffic assignment model is used. In this study, the pricing of the urban expressway is examined.

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In addition to free flow state and congested flow state, this study establishes the third phase of mixed flow state based on the q-k state using 5 minutes data, and carried out a comparative analysis, which investigates an impact of the three phases of traffic states on traffic accident risk. Firstly, in order to consider difference in the process of mixed flow state, this study analyzed the differences between the traffic accident risk on two-lane expressway and four-lane expressway. After, focused on an impact of a heterogeneous mixed flow state that appear when free flow state and congested flow state are mixed in space on accident risk, the relationship between the traffic states on each lane and traffic accident risk were analyzed. Using the accident record and the observed traffic data, this study analyzed the accident risk on the Hanshin Expressway network. As a result, it is shown that the accident risks of rear-ender collision and minor collision tend to be higher in the homogeneous congested flow comparing to ones in the heterogeneous mixed flow.

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The rat-run traffic flowing into the community road is a big problem in terms of traffic safety. Physical device, such as a constriction or hump have been used in the existing measures. However, these measures can't remove only rat-run traffic from community road. It is not a fundamental solution of the problem. Therefore, we focused on the rising bollards that are popular in Europe. The Rising Bollard can make it pass only vehicles with authority by making it go up and down the bollard made of steel automatically. It has not been introduced yet on public roads in Japan.
For the purpose of accumulation of the results of basic study of Rising Bollard, we conducted experiment in Saitama University campus in order to examine the possibility of installation in Japan. From experiments with subjects, inhibitory effect on passing the road is evident. This showed the efficacy against rat-run traffic. In addition, it was confirmed the operation in a bad situation, such as rain and snow and also confirmed the safety at the time of contact with the vehicle. It was possible to get useful knowledge for the installation.

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Traffic incidents cause heavy traffic congestion resulting in severe delays. Early and precise incident detection contributes early provision of information and incident handling to mitigate negative impacts of traffic incidents. Automatic incident detection algorithm has been introduced as freeway incident management system to detect incidents more early and precisely. Several conventional studies developed incident detection algorithms using observation data from roadside traffic detectors. However, it is difficult to install traffic detectors in the entire road networks because of their costs of installation and maintenance.
This study developed incident detection algorithm using information obtained from probe vehicles. By using the probe vehicle data, incident detection can be available in inter-urban freeways and developing countries' freeways where few traffic detectors are installed. The proposed algorithm is designed by checking the spatial difference of each probe vehicle's travel time and the temporal changes of the rate of flow at downstream of bottleneck. As a result of validation in microscopic traffic simulator, the algorithm has a certain accuracy.

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In order to perform the congestion measures, understanding the congestion locations and influence area is important. Depends on day-to-day traffic condition, congested location might change. In some cases, some congestion locations affect each other. For this reason, the identification of bottleneck-intersections and influence areas is difficult.
In this paper, we propose a method of identifying bottleneck-intersections and influence area of congestion using probe-data. The proposed method takes advantage of the relationship with the non-congestion and congestion of the road section and the road section. Results of verification major congested location examples, it was found that, it is possible to grasp the influence range bottlenecks-intersections using this method.

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Recently, using a bicycle is recommended under the growing concerns about health and environment, while the bicycle involved collision rate tends to increase. Some remarkable researches pointed out that a sight distance or driver's behaviors at intersections have affected an significant influence on bicycle safety, but the relationship between these factors are not clearly described together. Therefore, the purpose of this study is to investigate the possible factors of bicycle related accidents focused on the sight distance and driving behavior at unsignalized intersections along highway.

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Hump was legally accepted as a part of road structure after the revision by the Road Construction Ordinance in April 2001 as a traffic calming measure. Then various researches on hump have been conclude as a traffic calming measure in community road. In this research, the effect when humps combined with chokers set up on the community road was examined. In addition, comparison which paid its attention to form by installing the hump (a trapezoid hump and an arch hump) of different form in the same area was performed, and hump spread possibility was verified. As a result, arch hump has a higher speed inhibiting effect than trapezoid hump. In addition, about vibration and the noise, the trapezoid hump turned out that influence by the hump setting was smaller than the arch hump. There is a possibility for hump to increase in the future from the installation of the adequate shape.

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