Traffic Characteristics and Capacity of Overtaking Lane Partly Occupied Traffic Control Zone of Four-lane Freeway

This paper studies the lane utilization rate, traffic flow distribution on the lane, lane changing characteristics, speed characteristics and road capacity of the four-lane freeway traffic control zone which overtaking lane is partly occupied. The flow distribution curve, lane changing direction and lane changing rate curve, and velocity distribution curve of each main section in the carriageway and overtaking lane in the traffic control zone were obtained. The Greenshields model describing the relationship between velocity and flow was calibrated, and the capacity of each main section was determined accordingly. The results show that when the traffic flow is at a low level, the utilization rate of overtaking lane is low, only about 20% of the normal level. At this time, lane division, lane setting and traffic control mode should be optimized and adjusted. At the low level of traffic flow, the average speed and running speed of the traffic control zone are both high, so the running speed should be used as the value of the speed limit value. The capacity of the activity area in the traffic control zone is the lowest, only about 89% of that of the normal section. On the premise of ensuring traffic safety, efforts should be made to improve the capacity of the bottleneck section, and the section capacity should be taken as the basis for determining whether to carry out forced diversion. Copyright © 2020 by Science Press.