Microscopic Risk Analysis of Rear-End Collision on Tokyo Metropolitan Expressway

Abstract

In this study, a specific traffic flow condition observed just before rear-end collisions is identified, which can be utilized for reduction of those crashes by means of detecting the risky situations in advance and warning drivers. The study site is a sag which is located at upstream of Tanimachi JCT on Tokyo Metropolitan Expressway Route 3 (Tanimachi JCT direction), where rear-end collisions frequently occur. Using pulse data collected by traffic detectors, speed fluctuation characteristics of individual vehicles were analyzed. A speed drop and its propagation to upstream were considered for identifying the risky traffic condition, and the frequency of that situation on the study site is presented in this paper.