In the coordinated signal control of a corridor with 15 signalized intersections, it is found in previous studies that there are a lot of offset patterns to minimize delay time, which is equal to or bigger than the theoretical minimum delay time. The reason why there are a lot of offset patterns is that even if delay time of either one link could be minimized, it is impossible to minimize the adjacent link at the same time, and vice versa. According to the clustering results being converged by similar patterns with the clustering technique proposed in this study, these results have the tendency to give a priority to either direction with direction switching at some intersections. The result suggests the equalization possibility of delay time for both directions along a corridor with changing the direction of priority offset at some intersections. The study proposes an offset pattern search method to take balance of three elements (delay time, number of stops, and directional equality) by the pareto optimum.

The presence of metamessages has become apparent at the scene of receiving test results regarding cognitive function test for older drivers. Therefore, the revised Road Traffic Law (May 2022) has been enforced and the cognitive function test program has been changed. In this study, we verified the validity on the change to the test program by analyzing the metamessage easing effect of the new version of test result notification. A web-based survey experiment consists of a pre-questionnaire, a simulated cognitive function test, presenting of the test results, and a post-questionnaire, targeting 2,000 drivers aged 65 or older. As a result, the new test result notification had an effect on ease confidence in driving compared to the old version. However, classification 2 drivers before the program change have a risk of receiving a new metamessage when they are judged as " no risk of dementia" after the program change.

In this study, we proposed a conflict index n-PIC (normalized-Polygon Index for Conflict) that is calculated by dividing the sum of the side lengths of polygons with each vehicle and the restriction start point as vertices by the number of vertices, for merging and parallelly running vehicles at the upstream end of road work regulation. Using vehicle running trajectory estimation data based on video observation, we showed that the conflict index can be applied to risk assessment of situations where merging is forced at the upstream end of restriction, and continuously before and after merging, in comparison with conventional conflict indexes. Based on the discrimination score of the lane-changing model re-identified using observed data in unregulated sections and the n-PIC value, the high/low risk threshold was set at 30.0m. In addition, a certain degree of suitability was confirmed for classification based on discriminant scores and n-PIC values from 33 cases of unregulated conditions (excluding high traffic flow rates) and 6 cases of high risk under regulated conditions. Furthermore, the difference in the average extreme acceleration values between the 34 low-risk and 28 high-risk cases, classified by n-PIC value, was highly significant for each sign.