On the Risk of Traffic Accidents on Provisional Two-lane Expressways

抄録

In Japan and other countries, sections of expressways are opened as provisional two-lane expressways to facilitate the early development of expressway networks. Although this is beneficial in lowering initial expenses, the impact of number of lanes on traffic accidents is not yet clear. Hence the goal of this study was to analyze the risk of traffic accidents on provisional two-lane expressways in Japan. To minimize the effects of human factors such as fatigue and local environmental factors such as dynamic traffic conditions, we concentrated on the boundaries where the number of lanes varies within the same route à la regression discontinuity design. According to the estimation findings using generalized linear models, the risk of traffic accidents is higher on provisional two-lane expressways than it is on four-lane expressways around the boundaries.