Analysis of long-term change of space clearance between queued vehicles at signalized intersections

Abstract

Traffic congestion continues to occur at many intersections in Japan, obstructing the smooth flow of traffic. On the other hand, in recent years, the long-term reduction of traffic capacity on expressways has been attracting attention, and this phenomenon may also apply to ordinary roads. In this study, we focus on the space clearance between queued vehicles at signalized intersections, and investigates whether or not the distance changes over time, and the effect of such changes on traffic flow.

As a result, space clearance have been gradually increasing, especially since the 2000s, and the increase is about one meter greater than it was 30 years ago. The results of the study suggest that the increase in space clearance is not necessarily due to the type of vehicle, but rather to changes in driver behavior. It was also found that a one-meter increase in space clearance resulted in a 15% increase in the length of the queue at intersections.