车辆提前减速进入居民小区会形成一个交通瓶颈, 尤其在晚高峰期间会明显降低道路通行能力. 基于考虑慢启动效应的 VDR(velocity dependent randomization) 模型, 并引入期望时间反映车辆进入小区前的提前减速行为, 研究了单向单车道和双向两车道两种情况. 模拟结果显示: 当入区概率较大时, 存在一个临界进车概率, 当进车概率大于临界值时, 出现一个流量平台. 临界进车概率及其对应的流量值随入区概率的增加而减小; 当进车概率小于临界值时, 双向两车道系统流量要大于单向单车道. 双向两车道时路段上存在 3 个瓶颈, 即小区入口以及上下游路口. 小区入口与路口保持一定距离, 可减少瓶颈之间的干扰, 则小区入口位置的变化对道路通行能力的影响不明显.

Vehicles decelerate in advance when entering a residential area, forming traffic bottlenecks. Especially in evening peaks, vehicles returning to residential areas will significantly reduce road capacity. This paper introduces anticipation time to reflect the deceleration behavior of vehicles before entering the residential area based on the velocity-dependent randomization (VDR) model. Both the one-way, single-lane system and the two-way, two-lane system are studied in this paper. The simulation results show that there is a critical injection probability when the entry probability is large enough. When the injection probability is greater than the critical value, a traffic platform appears. The critical injection probability and its corresponding flux value decrease with increasing the entry probability. When the injection probability is less than the critical value, the flux in the two-way, two-lane system is greater than that in the one-way, single-lane system. There are three bottlenecks in the two-way, two-lane system: the entrance to the residential area and the upstream and downstream ends of the road. When the entrance to the residential area is not close to the ends of the road, the influence of the entrance location on road capacity is negligible.