The authors have formulated the minimum delay and an offset pattern which realizes the delay for the simplest one-link/two-intersection coordination. In this paper, the coordination control of fifteen signalized intersections with no turning vehicles is discussed. A concept of pillar (including critical) intersections located at the lowest coordination effect is introduced, and the authors introduce "pillar theoretical minimum" delay, which is the sum of theoretical minimum delay for all the pairs of pillar intersections replacing the original section of signalized intersections, as the lowest limit for actually achievable delay for the original section. The actually achievable minimum delay for the section should be at the middle of the "pillar theoretical minimum" delay and the delay with a priority offset pattern, which is defined as a combination of offset patterns with priority for either direction of separated sub-sections by the critical intersections. In addition, there are a lot of offset patterns which realize the actually achievable minimum delay.

There are concerns about the existence of metamessages at the scene of receiving test result notifications regarding cognitive function test for older drivers. In this study, we conducted a web-based survey experiment consists of a pre-test questionnaire, a simulated cognitive function test, presenting of the notifications of test results, and a post-test questionnaire targeting 2,000 drivers aged 65 or older, in order to measure the effects on the notifications of test results that the designs and layouts were changed to ease the metamessages. First, the results of the exploratory analysis between individual attributes and the susceptibility of metamessages revealed that the scores of "confidence in driving" and "self-evaluation of driving" increased on women and elderlies. It can be said that this is a side effect not intended by the survey designers. Second, compared to the current notifications of test results, the revised notifications of test results which took measures to ease the metamessages significantly decreased "confidence in driving" in post-tests.

According to the road vision published by the Ministry of Land, Infrastructure, Transport and Tourism, “residential roads where pedestrians and cars coexist with safety and comfort are ensured” were cited as ideal roads aimed for in 2040. Additionally, since the development and research of self-driving cars has been actively conducted, the situation of pedestrian and self-driving car pass by each other is considered to increase in the future. For the spread of self-driving car, it is important for drivers to be able to ride without feeling fear in such situations. Therefore, this study focused on the situation where pedestrians and cars pass by each other, and investigated what kind of behavior of the car gives the driver a sense of fear. In consequence, it quantitatively reveals what velocity and distance between pedestrian and car effect the driver feels fear. Furthermore, among the deceleration behaviors, we focused on the degree of deceleration and the final speed, and clarified their effect on the sense of fear.