Effect of directional flow ratio on signalised intersection control strategies

Abstract

A signalised intersection phasing is a multiple arm movements whereas staging is a single arm movement of vehicles at the onset of inter-green light. The purpose of the paper is to determine the extent to which highway traffic directional ratio can be accountable for the effectiveness of signal timing. Phasing and staging would be treated as mutual exclusive movements under varying directional traffic loading. Based on the hypothesis that percentage of directional split would influence traffic signal optimum performance and associated delays, directional split impact studies were carried out in Skudai town, Johor, Malaysia. Major roadway delays for traffic flows with 20/80; 30/70; 40/60; 50/50 incremental directional ratio were analyzed. Results show that phasing signal settings are best suited to 40/60 and 50/50 directional flow and staging for 20/80 and 30/70 directional traffic flow. The paper concluded that optimized signal setting based on phasing would be more effective in circumstances where the likelihood of 50/50 and 40/60 directional split are more likely. The same cannot be said of 70/30 or 80/20 directional split