Critical Traffic Volume Warrant of Signal Installing at Equal Weight Intersections

This paper presented the method of determining critical traffic volume for installing traffic signal based on actual traffic situation in China. Considering the condition that all approach traffic streams have equal right to pass through at some special unsignalized intersections, the model of Motorcade Analysis Method was improved by introducing the lost time of saturated discharging, and then the model of vehicles average delay under equal weight condition was proposed applying the probability and queuing theory. Furthermore, by comparing the average vehicle delay before and after signal control and choosing the lower one as the optimal control pattern, the critical volume curve of installing traffic signal for cross pattern 2/2 were presented. This research may provide a new theory reference in the progress of installing traffic signal.