Signal control strategy between expressway off-ramp and on-ramp area in Beijing

This paper mainly focuses on different influences on traffic flow in large traffic flow conditions, caused by different distances between off-ramp and on-ramp on expressways. In addition, a signal control strategy on side road is proposed and discussed. Our research is based on traffic simulation software (VISSIM). In this research, the characteristics to describe traffic features include average travelling speed and density. Specifically, we simulate 5 scenarios with different on-ramp and off-ramp distances from 200m to 600m and analyze features of traffic flow and their relations with the distance. When the distance decreases to 200m, traffic states deteriorate significantly. Therefore, the scenario with the distance of 200m is focused, and a signal control strategy on side road is used to alleviate congestions on side roads and expressways. After simulation with the strategy, comparisons and analyses are also given in this paper.