引入网络影响分析的道路选线优化模型

提出一个基于遗传算法的道路选线优化模型,该模型首先随机生成新建道路空间位置的候选方案集,并依据GIS平台自动设计新建道路的平竖曲线,并计算其各项工程费用;接下来,分析变化了的路网的拓扑结构,并在新路网中分配OD交通量,获得OD交通在新路网上的交通流特征,进而计算OD交通量的走行时间和在路网上的环境负荷;然后,利用工程费用、OD交通走行时间费用和环境负荷当量费用构造适应度函数,以判断各候选方案的优劣,同时实施选择、交叉、变异操作以获得更多的候选方案,直至得到一个最佳的新建道路方案为止。数字试验结果显示:新建道路对路网的影响不容忽视。

Road Alignment Optimization Model Incorporating Network Impact Analysis

Authors proposed a road alignment optimization method based on genetic algorithm.Firstly,alternatives of location of new constructed road were generated randomly,and then,horizontal and vertical curves of the road were designed automatically and all of the engineering-related costs were calculated by GIS.Secondly,topological structure of the changed road network was constructed automatically,and flow characteristics of OD traffic on the network were obtained through OD traffic volume assignment,and then total travel time of OD traffic volume and traffic environment loads on the network were estimated.Finally,the fitness function consisting of engineering costs,travel time cost and environment load cost of OD traffic was built to judge the alternatives.Simultaneously,more alternatives were obtained by applying operations of selection, crossover and mutation,and the process will be repeated until the optimal road alignment was obtained.Numerical experiment results show that the being constructed road is very important to the road network.