针对城市公交系统应急区域疏散路径规划问题,采用时间扩展网络建模技术对疏散公交路网进行了表达,进而建立了以疏散总出行时间最小化为目标函数的离散、动态疏散网络流模型,将公交网络的疏散路径优化问题转化为混合整数规划问题,并设计了启发式禁忌搜索(TABU)算法,用于快速求解公交疏散路径优化方案.最后,以长春市中心区路网为例,对公交系统的区域疏散问题进行了实证研究,着重对比了CPLEX9.0软件的精确求解与禁忌搜索算法的近似求解之间的性能差异.数值实验结果表明,时间扩展网络模型可以有效反映公交疏散系统的动态性,同时禁忌搜索算法能够在求解效率和求解精度上取得较好的折衷.
This paper deals with the route planning of public transit in urban road network for regional evacuation in emergency. In the investigation, first, the public transit evacuation system is modeled by using a time-expanded network. Next, a discrete and dynamic network flow model to minimize the total evacuation time is established, which transforms the route planning problem into a mixed integer programming (MILP) one. Then, a heuristic ta- bu-based search algorithm is designed to find out a high-efficiency solution to the route planning. Finally, a case study is conducted for the central road network of Changchun City in China, and the difference between the accurate results obtained from CPLEX9.0 and the approximate ones obtained from the tabu-based search algorithm is re- vealed. Numerical results indicate that the proposed time-expanded network-based model effectively represents the dynamic property of public transit evacuation system, and that the tabu-based algorithm reaches a compromise between the solving efficiency and the accuracy.