考虑交通事件影响的动态交通信号控制策略

采用数值仿真方法评价了固定式信号控制、延误最小自适应信号控制与通行能力最大自适应控制3种典型信号控制策略下的路网动态运行效率; 采用双排队模型构建了动态交通流仿真平台, 提出了交叉口流量传输优化模型, 分析了双排队模型中交叉口内交通流运行的状态; 假定用户依据瞬时用户最优原则选择路径, 提出了考虑信号控制惩罚时间的瞬时用户最优约束; 以系统总行程时间、有无交通事件影响的行程时间为评价指标, 研究了低、中、高3级不同交通需求下的信号控制效果。试验结果表明: 在低、中级交通需求下延误最小自适应控制策略的系统总行程时间最小, 比通行能力最大自适应控制在无交通事件影响下总行程时间分别降低0.45%和0.18%, 在有交通事件影响下总行程时间分别降低5.95%和2.52%;在高级交通需求下, 通行能力最大自适应控制总行程时间最小, 对比延误最小自适应控制, 在有、无交通事件影响下系统总行程时间分别降低5.46%、5.31%;对比有无交通事件影响下系统总行程时间变化幅度, 固定式信号控制在不同交通需求下均表现出最高的稳定性; 在低、中级交通需求下, 延误最小自适应控制策略较通行能力最大自适应信号控制策略更稳定, 在高级交通需求下, 两者的稳定性无显著差异。可见, 当交通需求较大时, 应提升交叉口通行能力, 当交通需求较小时, 应降低车辆延误。 

Dynamic traffic signal control strategies considering traffic incidents

The numerical simulation approach was applied to evaluate the dynamic operation efficiency of road network under 3 typical traffic signal control strategies, including the fixed traffic signal control(FSC), the adaptive signal control minimizing vehicle delay(ASC-VD), and the adaptive signal control maximizing intersection capacity(ASC-IC). The dynamic traffic simulation platform was constructed by the double queue(DQ) model. An intersection traffic flow transfer optimization model was proposed, and the running state of traffic flow at the intersection in the DQ model was analysed. It was assumed that the users selected their routes according to the instantaneous user optimal(IUO) principle, and the IUO constraint was proposed considering the penalty term caused by the traffic signal control. The system total travel time and the travel time affected by traffic incidents or not were taken as evaluation indexes, the signal control effects under low, medium and high levels of traffic demands were studied. Analysis result shows that under the low and medium levels of traffic demand conditions, the system total travel time of ASC-VD is the lowest. Compared to the ASC-IC, the ASC-VD reduces the system total travel times by 0.45% and 0.18% without the influence of traffic incidents, respectively, and by 5.95% and 2.52% with the influence of traffic incidents, respectively. Under the high levels of traffic demand condition, the system total travel time of ASC-IC is the lowest. Compared to the ASC-IC, the ASC-VD reduces the system total travel time by 5.31% without the influence of traffic incidents, and by 5.46% with the influence of traffic incidents. Compared with the change range of system total travel time with or without the influence of traffic incidents, the FSC shows the highest stability under different traffic demands. Under the low and medium levels of traffic demand conditions, the ASC-VD performs more stable than the ASC-IC, while under the high level of traffic demand condition, the stabilities of the two strategies have no significant difference. Therefore, when the traffic demand is high, the intersection capacity should be improved, and when the traffic demand is low, the vehicle delay should be reduced.