基于双层规划模型的城市快速路匝道优化设置研究

摘要

Ramp settlement is a key issue in design of urban expressway. Through analyzing ramp configuration, the paper investigated the road networks along urban expressways.The bi-level programming model was used to describe the problem. In this model, the upper part considered the transportation planner's perspective in order to design an optimal network structure and achieve systems optimization. The lower part of this model showed respect to the network users in order to attain the variable demand equilibrium. The upper model was solved by the genetic algorithm and the lower model was solved by the excess-demand algorithm. Result from an example revealed that the model could significantly improve the traffic operation quality, and get a reasonal plan for ramp settlement. Therefore, it provided a piece of scientific evidence for transportation planners to develop effective traffic solutions.%匝道设置是城市快速路设置的关键问题之一.本文通过对匝道设置问题的分析,对城市快速路周边道路网络设计问题进行深入的研究,并采用双层规划模型描述问题.其中上层规划模型是从交通规划者的角度出发,在各种约束的前提下,设计合理的匝道布局,使得交通出行达到系统最优:而下层从用户的角度出发,采用变需求的用户平衡模型来描述用户的出行规律.上层模型采用遗传算法求解,下层模型采用超量需求法求解.算例的结果表明,该算法能得到合理的匝道设置方案,从而为规划者决策提供科学依据.