车道功能与信号控制协同优化方法与实证研究

Collaborative Optimization Method and Empirical Study of Lane Function and Signal Control

为了提高城市道路资源利用率,缓解城市道路交叉口交通需求与供给在时间尺度上不匹配的问题,提出了一种信号交叉口动态车道与信号配时协同优化方法。首先,考虑进口道数量、车道功能及信号配时等时空资源参数约束条件,以交叉口饱和度方差之和最小为优化目标,构建了以车道功能和信号控制为决策变量的车道功能与信号控制协同优化模型。然后,设置了仅信号优化、车道功能与信号配时分步优化和二者协同优化3种方案,运用数值计算与仿真分析方法,通过Python软件输出了3种方案在不同交通需求场景下的车道功能和信号配时方案,并以车均延误为评价指标进行了效益对比,验证模型的有效性。最后,构建了工程化实证控制系统,选取杭州市典型交叉口进行了实地部署验证。结果表明:相比分步优化方案,提出的协同优化方法对降低交叉口的车均延误整体有积极影响,在高流量交通需求下尤为明显,通行效率最高提升14.7%;相比仅优化信号方案,通行效率最高提升30%;实证中,交叉口进口道可以实时切换可变车道功能,左转与直行车辆车均延误综合降低6.7%,表明提出的方法具有一定工程可行性,可以最大程度利用交通时空资源,有效缓解交通流方向性不平衡造成的交通拥堵。

In order to improve the utilization rate of urban road resources and alleviate the mismatch between traffic demand and supply at urban road intersections in time dimension,a collaborative optimization method of dynamic lane and signal timing at signalized intersections is proposed.First,considering the constraints of space-time resource parameters such as the number of entrance lanes,lane function and signal timing parameters,taking the sum of saturation variances of intersection as the optimization objective,a collaborative optimization model of lane function and signal control with lane function and signal control parameters as the decision variables is constructed.Then,3 schemes,i.e.,only signal optimization,step-by-step optimization of lane function and signal timing,and collaborative optimization of the two,are set up.By using numerical calculation and simulation analysis methods,the lane function and signal timing schemes of the 3 schemes under different traffic demand scenarios are output by using Python software,and the benefits are compared with the average vehicle delay as the evaluation indicator to verify the effectiveness of the model.Finally,an engineering demonstration control system is constructed,and a typical intersection in Hangzhou is selected for field deployment and verification.The result shows that(1)compared with the step-by-step optimization scheme,the proposed collaborative optimization method has a positive influence on reducing the average vehicle delay at the intersection,especially under the high traffic demand,the traffic efficiency is increased by 14.7%;(2)compared with the only signal optimization scheme,the traffic efficiency can be improved by 30%at most;(3)in the demonstration,the entrance lane of the intersection can switch the function of variable lane in real time,and the delays of both left turn and through vehicles can be reduced by 6.7%,indicating that the proposed method has certain engineering feasibility,it can maximize the use of traffic space-time resources,and effectively alleviate the traffic congestion caused by the imbalance of traffic flow direction.