A Study on the Comparison of Traffic Flow on Tokyo Metropolitan Expressway Over Time Using Traffic Detector Data

Abstract

In recent years, several studies have pointed out changes in traffic flow on expressways over time, and the investigation of the causes of these changes has become an urgent issue. In light of this, the purpose of this study is to clarify the changes over time in traffic flow at several points on the Metropolitan Expressway by comparing three different period and to examine the causes of these changes. From a macro perspective, a comparative analysis of QV diagrams and 99% tile value traffic volumes and speeds was conducted, and from a micro perspective, a comparative analysis of speeds, traffic volumes, and time headway within the platoon before and after the breakdown was conducted. As a result, in general, the QV diagram showed a shrinking trend, the 99% tile value traffic volume and the traffic volume before and after the breakdown showed a decreasing trend, while the rate of platoon generation before and after the breakdown showed an increasing trend. The statistical analysis suggested that changes in traffic volume are affected by changes in average time headway, heavy vehicle ratio, number of vehicles constituting a platoon, and platoon generation rate.