Evaluation of Collision Potential at Four- Legged Unsignalized Intersection Using Traffic Conflict Technique

Abstract

The counting of traffic conflict allows the estimation of accident potential at a particular location such as at-grade intersection. The objective of this paper is to examine the evasive action of driver occurs with some frequency at Shao intersection which may result in potential accident. This paper applied traffic conflict techniques to evaluate collision potential at unsignalized intersection located at Shao. The morning and evening peak traffic flow was captured using a video camera for seven days and then analyzed by playing back the video on daily basis. The 100 sample size of observed conflict was based on 95% confidence level, 5% permitted error and the proportion of the vehicles that were involved in a specific conflict for the observed traffic flow. The conflicts identified were compared with volume counts at minor approach. The daily peak hour approach traffic volumes were found to have a close relationship with the percentage values of conflict on the two minor approaches. It also showed that rear end collision accounted for more than 70 percent of traffic conflicts and it correlated well with the traffic volumes on WB and EB approaches.