面向常发拥堵点的交通信号协调控制方法

针对高峰期间常发拥堵点交通需求过大、周边关联交叉口交通负荷分布不均的问题, 研究了面向常发拥堵点的交通信号协调控制方法。通过对常发拥堵点的车流进行追踪与溯源, 根据交通量关联度确定信号协调控制范围, 然后基于路径的流量分担率与路段平均饱和度识别信号协调控制范围内的关键路径。基于宏观基本图理论, 考虑关键路径对路网运行状态的影响, 构建边界交叉口主动限流控制模型。同时, 利用元胞传输模型描述交叉口与路段的运行状态, 以关键路径通行能力最大化和进口道饱和度均衡化为信号控制优化目标, 建立均衡路网交通负荷的信号控制优化模型。以武汉市发展大道青年路交叉口以及关联交叉口为对象开展仿真实验, 结果表明: 虽然本文方法下的边界交叉口车均延误增加了6.8 s, 但常发拥堵点的车均延误降低了15.7 s; 关键路径的车均延误减少72.6 s, 平均排队长度减少26.1 m。并且, 路网整体的车均延误降低14.7%, 驶出车辆数增加26.6%, 验证了提出方法缓解常发拥堵点交通拥堵的有效性。 

A Coordinated Control Method of Traffic Signals for Recurrent Congested Network Locations

Traffic volume at recurrent congestion points is excessive, and the distribution of traffic load at associated intersections is unbalanced during peak hours. A coordinated control method of traffic signal for recurrent congestion points is proposed to solve the above problems. By tracking the traffic flow at the recurrent congestion point, the coordinated signal control area is determined according to a correlation of traffic volume. Then, the critical route of the coordinated signal control area is identified according to the traffic flow sharing rate and the average saturation of road sections. Based on the macroscopic fundamental diagram, an active perimeter control model considering the influences of critical routes on the state of road network is constructed. Meanwhile, a cell transmission model is used to describe the operating state of intersections and road sections. Maximum critical route capacity and equilibrium saturation of approaches are taken as the optimization objectives of signal control. A optimization model of signal control for balancing traffic load of road network is constructed. A simulation is carried out around the intersection of Wuhan Fazhan Avenue and Qingnian Road with its associated intersections. The results indicate that the average vehicle delay of boundary intersections increases by 6.8 s, but the average vehicle delay of the recurrent congestion point decreases by 15.7 s. The average vehicle delay decreases by 72.6 s, and queue length of the critical route decreases 26.1 m. Besides, the average vehicle delay of the road network is decreased by 14.7%, and the output traffic volume of the road network is increased by 26.6%.The simulation results verified the effectiveness of the proposed signal control method in alleviating traffic congestion at recurrent congestion points.