In this study, we developed a method to evaluate the potential for supplying transportation services through Green Slow Mobility (GSM) or other low-speed mobility solutions in areas with limited mobility. This method estimates potential demand for movement based on population distribution and the locations of facilities where daily movement is expected, and identifies regions suitable for GSM based on the constraints of available transportation capacity and operational distance. The results of the evaluation using the developed method revealed two key points. First, GSM is effective in approximately 45% of areas with potential mobility needs, considering operational distance and demand scale. Second, from a cost perspective, locations where GSM can be introduced under conditions of 20,000 yen per person per month or less account for only about 3% of the potential mobility demand, indicating that such locations are limited. Despite being limited, there are approximately 3,400 such locations nationwide.

Wire ropes have been installed on expressways as a safety measure on temporary two-lane sections where two-way traffic is required. While this has reduced the number of accidents involving vehicles veering into oncoming traffic, it has also increased the number of accidents involving vehicles coming into contact with the wire ropes. As a countermeasure, Akita and other prefectures have installed vehicle guide lines on the road on a trial basis to indicate where vehicles are traveling. However, the location of the road cross section and the type of lines that are most effective in guiding vehicles have not yet been clarified. Therefore, we will clarify these issues through driving experiments using VR. Based on the driving position in the road crossing direction and the results of the questionnaire survey, it was found that the vehicle guide line was most effective in stabilizing the driving position when it was placed 120 cm away from the outside of the dashed white line in the center of the road. The type of line, solid line, was found to be most effective in stabilizing the driving position.

The study examined the sustained effectiveness of Pace-Maker-Light (PML) on interurban expressways by comparing traffic capacity before and immediately after the implementation, up to three years after the implementation. The traffic capacity increased immediately after the implementation and decreased with each passing year until the following three years. However, the traffic capacity obtained from this study demonstrated a lesser decrease in traffic capacity over time than was observed before the measures were implemented. This finding suggests that the sustained effectiveness of PML measures is greater than the secular decrease of traffic capacity. In addition, while the congestion measure in the transverse direction in the previous study, which aimed to equalize a lane utilization, resulted in a sustained increase in the traffic capacity, the measure in the longitudinal direction in this study, which encouraged vehicles to adjust their speed, was not found to be effective enough to sustain an increase in traffic capacity.

On Community roads where various entities such as pedestrians coexist, reducing kinetic energy during a collision is essential. This study aims to analyze the relationship between the “mass” of a moving vehicle, which is directly related to the amount of kinetic energy, and accident damage on community streets and consider the significance of reducing the mass of a moving vehicle on the roads. Using open data on traffic accidents published by the National Police Agency, we analyzed the relationship between the degree of vehicle damage and vehicle mass estimated from vehicle size. As a result, the following findings were obtained. (1) The larger the size of a passenger car, the more minor the damage to its vehicle in an accident; (2) vehicle mass increases the damage to other vehicles instead of reducing the damage to the own vehicle; (3) it increases the overall damage in an accident, and (4) this tendency is particularly pronounced on community roads.

In this study, a construction signal cycle setting method was proposed for undersaturated flow for alternating one - way traffic on general roads. Nomograms were constructed to examine the effects of each variable on the construction signal cycle setting and to verify its applicability using field observation data. The nomograms which are presented in this paper demonstrated that traffic capacity increases in proportion to the length of the signal cycle, and that establishing a longer cycle length is an effective way to increase capacity when the length of the regulated section is long. In addition, field observation data validated that the cycle length estimated by the proposed formula is typically shorter than the actual cycle length due to the fact that the actual signal operation is conducted by setting slightly longer all red time. This tendency indicates that a buffer should be incorporated into the nomogram presented in this study.

In many regional cities and other central city areas, projects to promote urban walkability are underway to transform them into people-centered spaces. In response, academic studies have been conducted to clarify pedestrian circulation behavior and behavioral characteristics in commercial areas, but there are only a few studies that focus on children themselves. In this study, therefore, we observed children's movement in commercial area streets to understand the actual conditions of activity and examined the relationship between children's attributes and the walking environment. The results of the cross tabulation revealed that the occurrence of activity is related to age, accompanying persons, and walking environment. A multinomial logistic regression analysis was then conducted with these factors as explanatory variables and the occurrence of activity as the dependent variable. The results quantitatively revealed that activity is related to the ages, the accompanying persons, and the street environment, which are expected to be helpful in promoting future child-friendly town center walkability policies.

The Ministry of Land, Infrastructure, Transport and Tourism (MLIT) has set a goal of promoting traffic safety measures for school routes from FY2024 onward, taking an areal view of the area around elementary schools, in order to foster an awareness that “children's safety comes first in the area around elementary schools. Here, it is important to understand the trends of traffic accident characteristics around elementary schools according to regional characteristics in order to formulate specific measures and prioritize the content of the measures with respect to areal measures. Therefore, in this study, the area within a 500-meter radius of an elementary school, which is generally considered to be within the school zone, was classified into three clusters: “urban,” “suburban,” and “rural,” and traffic accident characteristics were compared by the degree of injury in each cluster. The results revealed that the trends of traffic accident characteristics differ according to regional characteristics, and that the factors that cause serious injuries and fatalities also differ.

Heavy winter snowfall causes severe traffic congestion in Sapporo. This study analyzes the effects of snow hauling/ widening and snow removal on traffic flow conditions. Breakdowns are considered to be one of the causes of traffic congestion. In this study, the area of hysteresis loops on the Macroscopic Fundamental Diagram (hereafter referred to as “loop area”) is used to capture the occurrence or non-occurrence of breakdowns. The hysteresis loop area is used in this study because the expansion of the hysteresis loop represents not only a decrease in average speed but also a decrease in traffic capacity. In this study, loop area is used as a proxy variable for traffic flow conditions, including the likelihood of breakdowns. Analysis of changes in the loop area showed that it tends to decrease with snow removal and widening. The results suggest that the loop area is effective as an indicator of the impact of snow hauling/ widening and snow removal on traffic flow conditions.