基于VISSIM的城市道路交叉口掉头模式评价

Evaluation on U-turn mode of urban road Intersection based on VISSIM

为评价城市道路交叉口不同掉头模式的安全性及通行效率,应用微观交通仿真手段,基于VISSIM仿真模型和交通安全替代评价模型(SSAM),对车辆的掉头行为进行仿真。采用平均排队长度、车均延误时间、车均停车次数、交通冲突类型和数量等指标,对城市道路三种典型掉头模式进行安全性及通行效率评价。结果表明:在任意行驶速度下,停止线前掉头模式产生的交通冲突量最少,交叉口内部掉头模式下车辆的排队长度和延误时间最小;综合评价可以看出,在车辆行驶速度低于50 km/h的情况下,采用交叉口掉头模式既可以明显减少交通冲突的产生数量,也对交叉口车辆通行效率影响较少,是三种掉头模式中的最优方案,行驶速度高于50 km/h的情况下,停止线前掉头模式最优。综上,通过对不同的掉头模式进行比选分析,建议通过参考车辆行驶速度选择较为优化的掉头模式作为该交叉路口的掉头模式。

In order to evaluate the safety and traffic efficiency of different U-turn modes at urban road intersections, the U-turn behaviors of vehicles were simulated using microscopic traffic simulation methods based on VISSIM simulation model and traffic safety alternative evaluation model(SSAM).Based on the average queue length, average delay time, average parking times, traffic conflict types and numbers, the safety and traffic efficiency of three typical U-turn modes on urban roads were evaluated.The results show that at any driving speed, the U-turn mode before the stop line produces the least traffic conflicts, and the queue length and delay time of vehicles in the U-turn mode inside the intersection are the least.Comprehensive evaluation shows that when the vehicle speed is lower than 50 km/h, the U-turn mode at the intersection can not only significantly reduce the number of traffic conflicts, but also have less impact on the vehicle traffic efficiency at the intersection. It is the best of the three U-turn modes. When the vehicle speed is higher than 50 km/h, the U-turn mode before the stop line is the best. Through comparison and analysis of different U-turn modes, it is suggested to select an optimized U-turn mode as the U-turn mode at this intersection by referring to the vehicle driving speed.