基于双层规划的交通疏散中车辆出发与交通控制综合优化

在有组织的区域性疏散中,从需求调节(即疏散车辆出发安排)和供给管理(即交通管控)两方面对疏散交通流进行合理组织,是提高疏散效率的有效途径。论文立足于疏散车辆出发组织与路网交通管控之间的双层决策关系,建立双层规划模型对集结点疏散车辆的发车频率、路线和交叉口控制参数进行综合优化,其中上层模型通过优化信号交叉口的相位绿灯时间即绿信比以降低平均延误,其决策影响到交叉口通行能力等供给特性;下层模型通过优化疏散车辆的分批出发时间与路线以压缩疏散总时间,其决策影响到交叉口流量等需求特性。设计了基于遗产算法的求解步骤,给出了一个数值算例。将模型优化方案和只从交叉口控制参数出发的单方面优化模式所得结果进行了比较,结果表明只从调整绿灯时间着手不结合车辆的出发组织,很难有效降低延误和压缩疏散时间。

Optimization of Vehicle Departure Arrangement and Traffic Control in Traffic Evacuation Based on Bi-level Programming

It is an efficient method to manage traffic flow genarated in an organized regional evacuation from two aspects: demand regulation (means to regulate the departure mode of evacuation vehicles) and supply management (means to control traffic flow in road network). Based on the bi-level decision relationship between departure arrangement and traffic control in road network, a bi-level programming model is presented to optimize the departure plan and control parameters of intersections simultaneously. The green ratio of signalized intersections appears as the decision variable of upper level to minimize the average delay, which will influence some supply characteristics such as intersection capacity; the departure schedule and routes of evacuation vehicles appear as the decision variable of lower level to minimize the total evacuation time, which will affect some demand characteristics such as flow through intersections. A genetic-based algorithm is presented, and a numerical example is given. By comparing the optimization results of the bi-level model and the results got from the optimization mode that only consider the control parametar, it is shown that the bi-level model really holds advantage in decreasing delay and evacation time.