A Comparative Study of Queue Discharge Characteristics at Signalized Intersections

Abstract:

This paper analyzed queue discharge characteristics of 11 straight ahead lanes at signalized intersections in Shanghai and Tianjin, China. The results show that the discharge process of queuing vehicles can be divided into three distinctive stages, i.e., the start up stage, the stable stage and the rising stage. The similarities and differences in queue discharge patterns were then compared with 17 straight ahead lanes in Nagoya, Japan. The results show that, in China, the average saturation headway was 0.05s larger, the average saturation flow rate was 80 pcu·h-1 lower, the average start up lost time was 0.83s shorter, and the passenger car equivalent was 7% larger. However, the headways compression phenomenon and the distribution of discharge flow factors were found to be similar in the three cities. Finally, one typical intersection in Shanghai was selected as the test site to analyze the impacts of different queue discharge patterns on signal timing and operational efficiency.