Dynamic speed management on motorways has been adopted in many Western Countries, while it is not common in Japan. This paper introduces the overview of the system, theoretical background and its effect on traffic flow and level of service based on literature reviews. Furthermore, the results of comparative analysis on the perception of the ordinary drivers to speed limits on motorways between Japan and UK are reported. Finally, we discuss the future challenges and possibilities for installing the dynamic speed management on motorways in Japan.
This paper introduces relatively new technological trends in engineering and enforcement approaches used for speed management. Specifically, this paper introduces the trends involving “Intelligent Speed Adaptation (ISA)” and “Average Speed Enforcement”, which have been studied and demonstrated in European countries since around 2000, and “portable Orbis”, which is a new speed enforcement technology in Japan. This paper then describes the approaches used to evaluate the impact of speed enforcement.
The maximum speed of certain sections of expressway were raised above 100km/h on a trial basis starting in November 2017. This paper reports the results of a study case that examines the impact this increase in the maximum speed had on traffic conditions. This study looked at the effect that the increase in the speed limit to 110km/h and 120km/h had from three different perspectives – changes in the travel speed, changes in the frequency of lane changes, and changes in the risk of collision when overtaking based on the margin-to-collision index. Although the data collected through to March 2019 did not show any significant effect of raising the maximum speed limit, some interesting changes were brought to light. The effects of raising the maximum speed limit will require further observation over a longer time span in the future.
The present study examined the effect of providing education aimed at reduction of the time-saving bias (referring to the driver’s cognitive bias of overestimating time saved by accelerating in a high-speed area), which affects the driver’s speed selection. Specifically, before measurement of the time-saving bias, twenty-seven university students with driver’s licenses were trained to calculate the time saved by accelerating when the speed was displayed as either “s/km” or “km/h.” The results of the present study indicated that the time-saving bias occurred in the former case, but not in the latter case. The findings also suggested that the extent of the time-saving bias was not related to the driving behaviors in the driving simulator.
In this paper, we examined the existence of regional differences in driving speed awareness, mainly between prefectures, using nationwide questionnaire survey data. Our results show that there were no regional differences in driver awareness of the road speed limit while driving on roads in terms of simple trends, namely differences in residential areas such as urban areas and rural areas and differences while driving between prefectures. On the other hand, when looking at the driver’s speed adjustment behavior in speed controlled zones or school zones, it was clear to see that speed adjustment behavior is similar in neighboring prefectures, but there are regional differences when the physical distance increases.
Road structure must be able to ensure safe and smooth traffic on both arterial and residential roads. This paper focuses on introducing traffic safety measures for residential roads, which are becoming more common in recent years, for measures to ensure safety and smoothness on roads in service. It also introduces concepts to ensure safety and smoothness in road structure from the perspective of “safety and smoothness”, “arterial and residential roads”, and “pedestrians and vehicles”.
This article introduces low-speed mobility, which is expected to be used in spaces of coexistence as a means of transportation in residential areas, etc., as one of the solutions to transportation problems in Japan, a super-aging society. First, I will introduce the types and categories of vehicles used for low-speed mobility, as well as their advantages and disadvantages. In addition, as utilization examples, I will indicate, for example, demonstration and commercialization cases, such as green slow mobility. Furthermore, I will introduce a demonstration experiment on low-speed mobility utilizing automated driving technology, and describe issues and future developments.
Among advanced logistics countries and regions, which has the strongest competitive power? Both the World Bank research, based on results from a global scale questionnaire, and my comparative empirical analysis on the competitive power of major logistically advanced countries demonstrate that the EU has an overwhelming competitive advantage. The purpose of this paper is to endeavor to find the source of the EU’s logistics competitive power. After considering alternate behavior of air and sea transport in major countries developed with the EU as the export base using two axes analysis for a postponement business model based on the expected freight rate and direct investment behavior, which is the trigger for such a model, it can be concluded that the EU’s logistics competitive power lies in their ability to rationally build an excellent business model that has the ability to self-adjust, which distinguishes it from others.