关键词: 交通工程, 双向左转车道, 车道缩减, 交通仿真模拟

Abstract: In order to study the distribution of right-of-way after lane reduction, to strengthen the system functions of non-motorized lanes and sidewalks, and to optimize the road space for both motorized and non-motorized lanes, four lanes were designed to reduce to three lanes with two-way-left-turn lanes. The traffic capacity of single motorized lane, non-motorized lanes and sidewalks was calculated and analyzed. Traffic simulation on three-lane and four-lane road section was conducted. Based on the optimal left-turn vehicle ratio rL,opt and the traffic flow Q for reduced lanes, the delay and traffic flow characteristics before and after road reduction were studied. The results show that the total traffic capacity of the road section based on human travel is increased by 15% after the “four to three” lane reduction design. And left-turn vehicles from different directions are able to enter the two-way-left-turn lane in advance and the interference resulted from lane changes in the same direction will be reduced. Therefore, both the average speed and the traffic capacity of single lane are increased. When Q＜750 pcu/h and the left turn ratio rL＜30%, it is suitable for lane reduction design, and when Q=750 ~ 1 125 pcu/h, careful operation is required.

Key words: traffic engineering, two-way-left-turn lane (TWLTL), lane reduction, traffic simulation