In recent years, there has been a growing emphasis on improving the sustainability of traffic safety infrastructure, which has led to considerations about removing unnecessary traffic signals. Specifically, prioritizing the removal of single-light traffic signals, which are easily replaceable by alternative safety measures, has become crucial. However, residents may not always support this, requiring a well-informed consensus-building process. To achieve this, it's essential to thoroughly assess the effectiveness of signal removal in reducing accidents and understand the factors affecting residents' approval or disapproval. This study aims to explore the changes in the number of traffic accidents before and after removing single-light traffic signals and the factors underlying these variations. In addition, local residents' attitudes toward signal removal and the factors shaping their opinions are analyzed. Our findings demonstrate that implementing appropriate safety measures after signal removal can effectively reduce accident rates. Furthermore, we show that raising community awareness in favor of signal removal can be achieved through clear information sharing and explanations.

In this study, we construct a simplified model of the speed control of an automated vehicle (AV) to avoid stopping a platoon of following vehicles in a coordinated signal-controlled corridor in which manual and automated vehicles are mixed. We then analyze how signal delays, number of stops, and CO₂ emissions vary depending on the AV penetration rate and signal parameters such as the (common) cycle length and offset. The analytical formula of the above three performance indicators and numerical results showed that (i) appropriate setting of the speed control interval of the AV can reduce the number of stops and CO₂ emissions without changing the signal delay, (ii) CO₂ emissions can be significantly reduced when the cycle length is relatively small and the offset is unfavorable from the viewpoint of the number of stops, and (iii) therefore, a small cycle length is desirable to maximize the effect of the AV speed control.

Traffic accidents carry severe consequences for both human life and property. Efficient traffic management necessitates not only a deep understanding of the underlying causes of these accidents but also the capacity to anticipate their severity. In this study, we delved into the factors that influence accident severity by analyzing data gathered from the Gotenba to Tokyo section of the Tomei Expressway in Japan during 2019. We applied a random forest model to a curated dataset of 701 cases to forecast traffic accident severity. Furthermore, a grid search was executed to pinpoint the optimal hyperparameters for this model. To evaluate the distinct impact of each factor on traffic accident severity, we utilized SHAP (SHapley Additive exPlanations) for visual representation. This methodology proved instrumental in highlighting high-risk variables and individuals. Significantly, our analysis pinpointed several findings, and one of these findings shown that accidents which transpired at the tail end of congestion zones exhibited a higher likelihood of severity. These robust findings pave the way for valuable insights that bolster expressway management.

In April 2023, the revised Road Traffic Law was promulgated, and electric kickboards are treated as specified small motorized bicycles. It is important to ensure safety and smoothness in road spaces where vehicles and electric kickboards are mixed. Therefore, in this study, measurements were made on five roads with different widths. The study then clarifies the effects of the different width configurations on the driving behavior of vehicles overtaking an electric kickboard, and based on this overtaking behavior, the safety and smoothness of each road is then evaluated. The results showed that safety and smoothness were reduced on narrower roads than the width configuration of a normal road. Furthermore, the results showed that on wide routes, the separation distance can easily be maintained at 1.5 m or more, and safety is not an issue. On the other hand, the results also showed that the smoothness of the road is reduced especially when the vehicle speed is high.

This study addresses the issue of accidents causing pedestrian fatalities due to vehicle violations at unsignalized pedestrian crosswalks. Efforts are currently underway to create safer traffic environments that prioritize pedestrians by combining physical infrastructure and traffic control measures. We focus on road surface markings and evaluate their efficacy in decreasing vehicle speeds. We installed road surface markings incorporating pictograms from an existing indication sign and pictograms based on a design index proposed in prior research at the same location. We evaluated the speed reduction effect on vehicles passing through a study section where a pedestrian crossing was positioned in the forward direction of travel. The findings from the analysis indicate that vehicle speeds were reduced across various points within the study section and that vehicle speeds decreased as they approached the pedestrian crossing when the road surface markings with pictograms aligned with the design indexes were present, in contrast to scenarios where such markings were absent.

On-street parking in time-limited parking zones controlled by a parking meters or parking tickets involves the payment of a fee. It is known from previous research1) that this fee payment rate is around 60%, but it varies depending on the purpose of parking, parking time, and parking characteristics such as whether the vehicle is left unattended or not. In this study, we conducted a statistical analysis of parking time and payment rates for parked parking and non-parked parking based on a survey conducted in the city center of Sapporo. This statistically shows that there is a significant difference in the fee payment rate when parking for more than 20 minutes and less than 20 minutes, and that there is also a difference in the payment rate depending on whether the vehicle is left parked or not. In order to encourage short-term parking on the street, regulations based on time-limited parking zones were established in the Road Traffic ACT 1972, but when compared with the current fee structure for off-street parking in 20-30 minutes categories, I think there is room for consideration if shorter time regulations.

While SA/PAs have become tourist attractions in recent years, the shortage of parking spaces at SA/PA has become a social problem. Stricter operation control in the freight industry has increased the demand SA/PAs, and space for over-sized trucks is becoming tight. This paper analyzes ETC/FF (ETC Free Flow) data from NEXCO Central Japan, in the Tomei and the New Tomei expressway. ETC/FF data is data that can be used to determine the entry/exit times of individual ETC vehicles at SA/PAs and IC entrances/exits based on the history of road-to-vehicle wireless communication devices installed at SA/PA entrances and exits. Using discrete choice models of SA/PA usage, the effects on congestion in parking lots were examined, and the effectiveness of measures to disperse parking demand at SA/PAs was tested using developed simulator model.

Recently, the number of accidents involving head-on entry into work zones has increased rapidly. While the direct cause of these accidents is often attributed to careless driving, one contributing factor is believed to the driver's dependence on the Advanced Driver Assistance Systems (ADAS). Furthermore, it is possible that present ADAS do not satisfy the activation conditions at the beginning of work zones. To address this issue, a series of driving experiments were conducted using vehicles from multiple manufacturers. The activation conditions of Advanced Emergency Braking (AEB) and Traffic Sign Recognition (TSR) were examined and compared. The results showed that the AEB did not activate against the current safety system, known as 'Anzen Taro.' Also, it was found that the maximum speed sign was recognized, although there was some variation in activation locations, and that the distance between the signs at the beginning of work zones was enough. In addition, it was suggested that the sign should be placed on the right side of the roadside strip depending on the road alignment.

A decline in response rates in social surveys has been observed that is partially attributed to a rise in refusals. To enhance the reliability of survey outcomes, various strategies must be explored for boosting response rates. However, the available research on the correlation between face-to-face survey conditions and response rates remains inadequate. This study investigates the impact of different survey conditions on the response rates of face-to-face interview surveys for parking users. The survey conditions included variables such as the gender of interviewers, whether the survey target was informed about the survey organization (a university), and whether interviewers wore armbands representing the survey organization. The survey, conducted in December 2022 in downtown Kumamoto, Japan, engaged 247 participants out of 471 potential respondents. The findings reveal a 25.4 percentage point increase in response rates when participants were informed about the survey organization, and a 14.6 percentage point increase when female interviewers were involved. These outcomes offer valuable insights for designing effective and efficient interview surveys.

In Japan, it is common for elementary school students to walk to and from school from the first grade. While many schools have implemented group school commuting (so-called "shūdantōgekō") as an effort to improve the safety of elementary school students, there have been quite few studies that had quantitatively revealed the traffic safety effects of group school commuting. Therefore, the purpose of this study is to analyze the effect of group school commuting on the frequency of traffic accidents among elementary school students. Specifically, we first conducted basic analyses and statistical modeling on the relationship between the number of elementary school students by prefecture, the percentage of schools that implement group school commuting, and the frequency of accidents involving elementary school students when commuting to and from school. In addition, we estimated the group school commuting trip rate using person-trip data for cities in Aichi Prefecture, and examined the relationship between it and the frequency of accidents involving elementary school students. The results suggested that group school commuting has a certain traffic safety effect.

The purpose of this paper is to analyze the present situation of municipal involvements in the consolidated transportation projects of passengers and cargos in Japan initiated during 2011-2021. Those projects using route buses and taxies by alliance of transportation and package delivery companies were analyzed based on the questionnaire surveys over the relevant municipal authorities. The principal findings are as follows: a) Although the degree of involvement of municipalities in the projects are various, the municipalities with deep involvement are all in depopulated regions. b) Most projects are operated only by alliances among private companies. c) A few municipalities actually incorporate the consolidated transportation of passengers and cargos in the relevant municipal plans to promote smooth consensus building among stakeholders. d) The national/prefectural subsidies to the projects are only utilized for the demonstration experiments. Based on these findings, this paper emphasizes the necessity of municipal involvement in the projects based on the recognition of that cargo transportation holds a fundamental position in local living environment in the depopulated regions, and the enhancement system to induce the benefit of those municipalities to take part in the projects.

Although the number of traffic fatalities in Japan reached a record low of 2,610 in 2022, it is necessary to continue efforts to reduce the number of traffic fatalities and the number of traffic accidents. This study identifies the characteristics of traffic accidents at intersections of residential streets by analyzing the relationship between the actual conditions of traffic accidents and factors related to the road structure and traffic regulations. This study found that some intersections have a high number of traffic accidents even when traffic volumes are relatively low. Intersections where a high number of accidents between automobiles and bicycles occur have the following four characteristics: (1) the road side margin distance is less than two meters, (2) the line of sight distance is less than two meters, (3) bicycles enter in the opposite direction of one-way traffic for automobiles, and (4) bicycles enter from the right side of the road.

Wrong-way driving on expressways could cause serious accidents. Expressway companies have implemented various wrong-way driving countermeasures that were publicly recruited in addition to conventional ones such as no-entry signs, arrow markings, and other warning signs. However, the evaluation of these measures has not been conducted yet. This study evaluated these countermeasures in a VR experiment, using videos that reproduce the scenes of wrong-way driving on expressways. Sixty subjects were asked to watch the videos and press a button whenever they felt the driving was dangerous. For each video, they were asked "Why did you feel dangerous?" to know whether they were aware of the wrong-way driving. The study analyzed (1) the ratio of subjects who noticed the wrong-way driving; and (2) the timing that they noticed wrong-way driving for each countermeasure. As a result, both of the conventional and publicly recruited countermeasures were effective in preventing wrong-way driving, and care should be taken to implement the publicly recruited countermeasures together with conventional ones.

In the process of promoting the use of bicycles in Japan, bicycle traffic infrastructure has been improved on roadways in various locations. However, a persistent issue has arisen in the form of low utilization rates even after these improvements. This study aims to explore methods to enhance the utilization rate of bicycle lanes by leveraging virtual road spaces. Through conjoint analysis, we have analyzed the factors related to road structure and traffic conditions that influence bicycle users' choices of passing places. The results have clarified that the figuration of the bicycle lane, the width of the first lane combined with the shoulder, and the width of the sidewalk significantly influence for bicycle users' choices of passing places. Therefore, it is suggested that in order to encourage the use of bicycle lanes on roadways, the key points are the width composition and shape in the space from the road shoulder to the sidewalk.

When verifying the effectiveness of congestion measures, traffic conditions at two different periods are commonly compared. Among the various congestion measures, the effect of changing road markings may decrease as users become accustomed to them, and its sustained effect has not been clarified. This study examined the effect of the congestion measures by comparing and analyzing the traffic conditions of the lane-keeping green line near Higashi-Matsuyama IC (outbound) and the solid-white lane boundary line near Oizumi JCT (inner), where the road markings were changed as the congestion measures. As a result, the study revealed that the increase in traffic capacity and the decline in the utilization rate of passing lane were sustained after the implementation of these measures at both locations. Furthermore, at Oizumi JCT (inner), the lane utilization rate had been balanced two years following the implementation of these measures, which suggests that traffic conditions had changed over time.

In this study, we improved the estimation system for vehicle trajectories to achieve both long observation ranges and high accuracy by using multiple video cameras installed adjacent to each other along roads. First, we applied a two-dimensional projective transformation formula to limit the control point setting on the road surfaces by separating the projection of the tracking point on the triangles that approximate the road surface and correcting the position coordinates for the gap between the tracking point and the triangles. Additionally, by setting the control points based on the screen coordinate values of the probe vehicle and the GPS positioning values, the road surface approximation triangle can be arranged evenly and efficiently. We set 734 road surface approximation triangles in the observation section of about 820 meters of the expressway, and the average Euclidean range was 0.1 meters, and the RMSE of the traveling speed was 0.5 km/h based on the positioning results of the probe vehicle.

Based on the studies that have shown a decreasing trend in the saturation flow rates at signalized intersections in recent years, there is a possibility that this trend is also occurring at railway crossings. Therefore, in this study, we observed the headways of vehicles passing the stop line at gated and signalized railway crossings. We also calculated the saturation flow rates and compared them with previous studies. The observed average headway at signalized railway crossings remains relatively constant from the fourth departure position onwards, similar to signalized intersections. On the other hand, at gated railroad crossings, the average headways remain consistent regardless of the departure order. Additionally, the saturation flow rates were determined to be 600-670 vehicles per hour of gate being open at gated railway crossings and around 1,500 vehicles per hour of green at signalized railway crossing. These represent a decrease of approximately 25 to 35% in the former and 8% in the latter compared to the saturation flow rates in previous studies.

One of the reasons for accidents occurring at unsignalized pedestrian crosswalks is that objects in the vicinity (visibility obstructions) are obstructing visibility between the driver and the people waiting to cross. Therefore, we quantitatively clarified the effects on visibility of the relationship between the location of visibility obstructions and the position of pedestrians waiting to cross by video observation. As a result, it was confirmed that the visibility between drivers and pedestrians waiting to cross was obstructed by the visibility obstacles. In particular, it was found that the distance at which a driver can see a pedestrian waiting to cross varies greatly depending on the location of visibility obstructions and the position of pedestrians waiting to cross. In order for drivers to be able to see waiting pedestrians from an appropriate distance, pedestrians need to be at least 1.8 m from the edge of the curb or at least 1.5 m to 2.3 m from the edge of the pedestrian crossing

In this study, we analyzed the holiday population flow with COVID-19 pandemic in the Tokyo metropolitan area using mobile spatial statistics which is a type of mobile phone location data. Specifically we examined time-series changes in trip generation and trip attraction by prefecture and distribution characteristics by trip distance using population data from residence to place of stay every four months from 2019 to 2022. The results suggested trip generation and trip attraction decreased as well as behavioral changes such as a shift to short-distance travel that under the declaration of a state of emergency in May 2020 and January 2021. In addition, from May 2021 onwards, trip generation and trip attraction increased gradually regardless of whether a state of emergency was declared, and the composition ratio by travel distance was almost the same as in 2019. This result suggests that travel behavior on holidays was close to pre- COVID-19 pandemic levels.

Demand transportation systems, which are pre-booked transportation services, have been widely implemented nationwide over the past few decades. Furthermore, in recent years, the utilization of AI technology has enabled efficient route planning and dispatch, as well as the ability to accommodate on-demand reservations. As a result, the improvement in convenience has led to an increase in demand. This study focused on AI on-demand transportation services in local small city. It aimed to explore appropriate fare settings through an analysis of the value of users' mobility. Moreover, the analysis was conducted using the Contingent Valuation Method (CVM), which is commonly used for measuring environmental values and similar purposes. Furthermore, using survey data and usage records, it was possible to conduct an analysis that considered factors such as usage frequency. The most significant feature of the data used in this study is the integration between the datasets. Finally, the user convenience was measured by using the feature of CVM.

The utilization of time series analysis has seen a significant surge, owing to the remarkable increase in the temporal granularity of data, primarily propelled by the widespread adoption of the Internet of Things (IoT) and the continuous enhancement of analytical capabilities. The primary objective of this research endeavor is to gain a comprehensive understanding of the intricate relationship between transportation demand and public interest through a meticulous regression analysis of various time-series datasets. In this context, the term "demand" pertains to the influx of visitors at roadside rest areas, and our dataset spans a duration of three years, with an additional one-year dataset provided by two distinct operators. The measure of "interest" is derived from the quantification of Twitter posts and newspaper reports related to these rest areas. The outcomes of our regression analysis unveiled a noteworthy association, indicating that a single tweet is linked with an approximate increase of either 5 or 25 visitors. However, it is imperative to underscore that our causal analysis has illuminated a unidirectional relationship, suggesting that the number of visitors exerts an influence on the volume of tweets, rather than the reverse scenario where tweets impact visitor numbers.

On urban expressways, it is important to analyze lane change behavior to facilitate traffic flow and ensure vehicle safety. There are few examples of analyzing this behavior using high-resolution vehicle trajectories, and it remains a qualitative classification. According to the reasons stated above, this study aims to conduct a basic study of a method for quantitatively understanding this behavior by applying unsupervised time-series clustering to Zen Traffic Data from the Hanshin Expressway, in which the trajectories of all vehicles are recorded at 0.1-second intervals. First, time series samples of lane change behavior were created. Next, those samples were classified in several ways depending on the definition of distance and the variables used. The results of the application were naturally understandable, and the applicability of the method was empirically demonstrated. In addition, the clusters obtained were interpreted in comparison with previous studies, suggesting new quantitative findings and outlining issues for method development.

To improve safe and secure walking environment on residential streets, it is important to make drivers attention of the existence of the crosswalk and pedestrians. The purpose of this study is to clarify the effects of the road environment and traffic, including the visibility of unsignalized crosswalks, on yielding behavior. A survey was conducted at 21 unsignalized crosswalks around Asahi-ku in Osaka City and around Showa-ku in Nagoya City. Using the results of the survey we analyzed the effects of the road environment and traffic on the yielding behavior. The main findings of this study are as follows. 1) The average yielding behavior rate at all unsignalized crosswalks surveyed in this study was 49%. The maximum yielding behavior rate was 89% and the minimum yielding behavior rate was 4%. 2) The yielding behavior rate was higher at single-lane crosswalks than at two-lane crosswalks. 3) The results suggest that the degree of clearly of crosswalk related to the visibility may affect the yielding behavior.

With the development of SNS, it is easy to obtain and disseminate trend information from Twitter (The official name is X, but we use Twitter in this paper). Nowadays, when a natural disaster occurs, information about the status of public transportation systems that are particularly affected is often shared by SNS. In this paper, we focused on traffic accidents (hereinafter called “accidents”) as familiar disasters and analyzed how they were posted and spread on SNS based on accident data in Tochigi Prefecture and data posted on Twitter. As a result, it was confirmed that the number of retweets related to accident information exceeded the number of regular tweets. Additionally, there was a tendency for the posting users to be those who liked cars. Posts that are retweeted by posts that match the location of the accident tend to include hashtags, images, videos, etc., and do not depend on the number of followers.

Heavy winter snowfall in central Sapporo has a significant impact on road traffic. XRAIN precipitation intensity can be used as a method to grasp snowfall conditions in real time and on an area-wide basis. On the other hand, MFD can represent changes in traffic conditions. In the present study, we analyze the relationship between XRAIN precipitation intensity and traffic conditions expressed by MFD in central Sapporo. First, the effectiveness of XRAIN precipitation intensity as a method to determine snowfall on the ground was verified by comparing XRAIN precipitation intensity with snowfall observed on the ground, and a strong correlation was found between the two. Next, the effect of XRAIN precipitation intensity on the shape of the MFD was analyzed, and it was found that hysteresis loops were generated in the MFD by XRAIN precipitation intensity, where congestion occurred. the results suggest the possibility of estimating traffic conditions from XRAIN precipitation intensity.

The authors’ past research highlights a significant positive shift in traffic behavior observed in participants who underwent traffic safety hazard prediction training (KYT) during a mid-to-long-term follow-up survey. However, the underlying factors responsible for this transformation remain undisclosed. This study aims to provide a comprehensive understanding of the factors contributing to changes in traffic behavior by utilizing ordered logit models based on data gathered from KYT sessions conducted in FY2020 and FY2021. The analysis yielded the following two findings: 1. Training with VR materials significantly affects road width, checking curve mirrors, checking back-ward, and walking on the right side of the road compared to the control group. 2. Training with photographic materials significantly affected right/left confirmation, road width, curve mirror confirmation, rearward confirmation, and walking on the right side of the road compared to the control group. These findings illuminated the distinct impacts of different training materials on traffic behavior and offer valuable insights for improving road safety education programs. Further research is needed to investigate the specific mechanisms underlying these effects.

In this study, we analyzed the characteristics of users’ avoidance behaviors through a driving experiment focusing about oncoming Electric scooter (E-scooter). Subjects were classified by gender, frequency of bicycle use, motorcycle license holder, and driving characteristics of passenger cars, and the offset distance and avoidance start position were analyzed for passing each other or between a bicycle and E-scooter. As a result, there was no significant difference in offset distance by gender. It was found that female tended to start avoidance later when passing each other by E-scooter. By frequency of bicycle use, people who do not usually ride bicycles tended to start avoidance earlier when the investigator was running at 0 meter. By motorcycle license holder, motorcycle license holders tended to have a larger offset distance and start avoiding the situation earlier. By driving characteristics, it was found that people who were confident in their driving skills started to avoid early.

The purpose of this study is to understand the decline in traffic performance on an interurban expressway over time at the micro level and to examine the factors that contribute to this decline. The analysis was conducted by lane and vehicle type based on vehicle detector pulse data from two time points in 2006 and 2019. The results showed the speed had generally decreased during non-congestion flow. Moreover, there was a change in the time headway. This change can be attributed to the change in lane utilization in bins of low-flow rate and to the rising number of drivers who drove with a margin and the overall reduction in speed in bins of high-flow rate. The breakdown flow rate had also declined due to the increasing number of vehicles which have long space clearance and do not follow the car in front during the time immediately before traffic congestion. Even if that kind of vehicles increase, the shock wave is caused and leads to the traffic congestion. The study also found that the space clearance during traffic congestion increased, and it affected the decline of the queue discharge flow rate.

Road safety education plays an important role in guiding participants to safety behavior. Many studies on behavior change have applied educational approaches, planned behavior theory, etc. as intervention methods, and correct understanding of road safety education and effective teaching/learning opportunities are required. In addition, naturalistic cycling data has been used to understand bicycle use behavior and evaluate safety, but few examples have been used to verify the effectiveness of education and learning. In this study, focusing on the process of behavior change through exploratory learning, the effects of workshop-style road safety education using electrically power assisted bicycle commuting to school on behavior change were quantitatively analyzed. The results showed that through workshops, the frequency of risky behavior improved, and risk avoidance behavior was increased, and in the process, the workshop influenced the participants to correct their overestimated self-evaluations, influence their motivation and sense of responsibility, and enhance their intention to change their behavior.

In this study, the authors investigated a bicycle safe driving support system: a small device on bicycles to provide appropriate safety guidance and alerts to children, based on the considerations of parents. The authors conducted a web questionnaire survey on parents who had the opportunity to go out on bicycles with their children, and developed a model that assumed expectations and concerns that influenced the intention to use a bicycle safe driving support system and analyzed the model using structural equation modeling. The analysis indicated that, whereas the age or gender of a child did not significantly affect the intention to use the support system, expectations such as being able to warn children without the presence of their guardians and having the effect of traffic safety education significantly influenced. Furthermore, concerns such as children having fun and intentionally causing warnings significantly influenced.

In recent years, in addition to GPS data and base station data from cell phones, improved image recognition technology has made it possible to detect people from images and determine pedestrian flow. On the other hand, the survey frequency of the National Road and Street Traffic Survey is once every five years, and OD traffic volumes are not updated until the next survey. For this reason, methods such as the above-mentioned inverse estimation of OD traffic volume utilizing observed flow data have been put into practice. Therefore, this study proposes a method to update the OD traffic volume from a past web-based survey conducted on campus to the current OD traffic volume by detecting people from cameras installed on campus and using the totaled pedestrian flow data. Note that since the cameras are installed on the road, people move in all directions. Therefore, we have realized a highly accurate updating of the OD traffic volume by taking the direction into account when totaling the pedestrian flow data.

Recently, there have been many cases of analyzing traffic volume and travel speed per route using probe data collected from automobiles. In addition, if the behavior of individual vehicles could be understood in terms of driving lanes, more advanced road traffic analysis could be realized, such as analyzing the behavior of lane changes at mergers and crossings. In this study, we devised a method to estimate the lane of driving of individual vehicles from ETC2.0 probe data, which has higher positioning accuracy than ETC2.0 probe data, by superimposing the driving trajectories of individual vehicles on a mesh divided by lane. Then, machine learning was applied to the time-series changes in the unique numbers assigned to the mesh. The results suggest that although the estimation results are affected by the positioning accuracy of ETC2.0 probe data, it is possible to estimate the driving lane of an individual vehicle with higher accuracy than when the positioning points are checked one by one.

The visually impaired who have to perform the task of crossing the road without visual information are being supported by guidance blocks for the visually impaired, acoustic traffic lights, etc. There are some cases where it cannot be used. The reliability of the step at the sidewalk-roadway boundary, which serves as a clue to determine the direction of crossing, varies depending on the crossing. In this paper, we conducted a walking experiment with the visually impaired at the station plaza in Tokyo where "orientation blocks", which have been proposed as a new road crossing support tool. We considered subjective evaluation from the user's perspective. As a result, the effectiveness and usefulness of the direction orientation block in a series of crossing actions was confirmed in terms of ease of direction orientation, confidence level, and peace of mind while walking.

In Japan, many cities are considering the introduction of LRT in order to solve various urban problems. It is expected that the introduction of LRT will not only provide a means of transportation, but also induce people to visit the city center, thereby contributing to the revitalization of the city center. On the other hand, it is difficult to continuously monitor the effects of the introduction of LRT using conventional methods such as questionnaire surveys. Therefore, in this study, we developed a method to estimate the behavioral characteristics of LRT users in Toyama City by smartphone location data. In particular, we clarified the actual behavior change of LRT users triggered by COVID-19. The analysis revealed that COVID-19 reduced the number of LRT users and at the same time, users significantly restricted their activities. This result indicates the usefulness of using smartphone location data to understand the actual status of LRT users, and suggests the possibility of utilizing this information for estimating the effects of LRT maintenance.

This paper describes an investigation into the motorists yielding behaviors to pedestrians at an uncontrolled crosswalk location. The study site in Sendai City, Miyagi Prefecture with rectangular rapid flashing beacons (RRFB) warning devices were used in this investigation. According to studies in the United States, the effectiveness of RRFB has been confirmed that the number of conflicts between vehicles and pedestrians at crosswalks decreased and drivers tended to give pedestrians opportunities to cross road safely. In Japan, authorities also have been struggled to ensure pedestrians right-of-way law by various measurements such as enforcement, education, traffic safety facilities etc., but there is not much knowledge on the effectiveness of crossing facilities using flashing lights. In this study, three elevated video cameras mounted on street lamps besides sidewalk were used to collect before-and-after data for installation of RRFB. The results showed that yielding by drivers increased 15.2 % after installation of RRFB over four months period, however it cannot be said that the flashing lights affected the drivers yielding behaviors because RRFB actuation rate at the experiment site was low.

In this study, we constructed a simulation evaluation system for delay-time feedback traffic signal control using probe data with a traffic simulator, a signal control framework, a probe emulator, and a signal control emulator. First, the OD traffic volume and saturation flow rates were set from the video observation data at Komazawa Street, and it was confirmed that the average travel time RMSE per minute from 6:50 to 9:30 by the traffic simulator was 53.3 seconds. Next, we formulated and coded an algorithm for estimating and updating the coefficient value of the average delay calculation model from the signal control parameters using the Kalman filter. It was confirmed that a certain level of accuracy was maintained in accordance with changes in traffic conditions, such as blocking-back. Furthermore, based on the coefficient value of the average delay calculation model, an algorithm was formulated to optimize the signal control parameters according to fluctuations in traffic conditions.

In Japan, parking facilities have been developed quantitatively to accommodate motorization. However, the entrances to parking facilities are located at each building, which divide the continuity of the streetscape and pedestrian space. Therefore, parking lots need to be aggregated for pedestrian walkability. Parking aggregation reduces the number of parking facilities associated with a building but increases the walking distance to the final destination from a parking lot. Therefore, it needs to understand the proper separated distance from the building to the parking lots. This study analyzed the effect of separated distance on parking lot aggregation in several districts in central Tokyo, focusing on the attached equipment-duty car park. The results showed that the longer the separation distance, promote parking lots aggregated, but there is the upper limit of parking aggregation when the separated distance exceeded a certain length. Therefore, parking aggregation should consider deregulation for parking and appropriate separated distance.

It is important that signal lights be properly positioned to prevent traffic accidents at intersections. Vehicle signal lights should be located in front of intersection to be effective in preventing traffic accidents. On the other hand, there is no knowledge on the location of bicycle signal lights. In this study, a bicycle simulator was used to examine the effect of the location of bicycle traffic signals on the stopping behavior of bicyclists. As a result, the following findings were obtained. 1.Regardless of the location of the signal for vehicles, the presence of a bicycle signal in front of the intersection has the effect of discouraging bicyclists from forcibly entering the intersection. 2. With the bicycle signal in front of intersection, subjects tend to be more likely to refer to the bicycle signal. These results suggest that the location of the bicycle signal would be more useful in the front of the intersection.

Fundamental diagram (FD) is a relationship that expresses the basic characteristics of traffic flow, such as traffic capacity, etc. Location-Dependent FD is the FD of each segment when a road is divided into segments with mutually different characteristics. Therefore, if the Location-Dependent FD can be properly estimated, the location and capacity of bottlenecks that cause traffic congestion can be determined. However, it is not easy to estimate the FD of a road by dividing it into appropriate segments based on actual traffic data. In this study, a method for estimating FD by dividing a road into segments with different characteristics was developed by applying sparse modeling using Connected Vehicle (CV) data (so-called " Probe Vehicle Data"), which have information on arbitrary points on the road, as input. The properties of the proposed method are validated by simulation-based and real-world-data-based experiment, and the estimation accuracy of the proposed method and future issues are shown.

In order to realize a smooth and safe intersection, the position of the signal light is an essential factor. Changing the position of the signal light (far type and near type) may affect driving behavior before and after passing through an intersection, such as automatic driving and signal control at intersections. However, the knowledge of the analysis considering the position of the signal lamp for various signal controls has not been sufficiently obtained. Therefore, in this study, we used data from a simulated driving experiment using a driving simulator to analyze vehicle behavior when changing signal control under conditions in which signal lamp positions were compared. Some of the signal controls of the far type tend to lead to driving behavior that increases the danger. In contrast, the proportion of driving behaviors that increase the danger of the near type is lower than that of the far type in all signal controls. The characteristics of driving behavior associated with the difference in signal lamp position were clarified.

In Japan, the number of traffic accidents is decreasing, but the number of the intersection collision is increasing. Previous research has confirmed that ``large number of branches'' and ``land use'' have an influence on collision accidents at unsignalized intersections. However, in order to consider safety measures, it is necessary to understand the number and structure of unsignalized intersections. Therefore, in this study created unsignalized intersections using open data for Aichi prefecture. The number of unsignalized intersections and the shape of intersections were collected, and the characteristics he intersection collision by age were tabulated. As a result, it was found that there was a difference between the ranking of the number of accidents and the ratio of the number of intersections, and that the ratio of accidents at deformed intersections was higher when looking at the ratio of intersections. In the future, aim to add intersection space factors and build a model for the occurrence of collisions at intersections.