蚁群算法下容量限制分配的路网结构可靠度分析

Analysis on Reliability of Road Network Structure by Traffic Allocation due to Limited Capacity Using Ant Colony Algorithm

为达到结合道路结构可靠度与道路网络可靠度的目的,分析了容量限制分配对道路网络结构可靠度产生的影响。容量可靠度采用交通统计的方法得出,并以容量可靠度0.4作为交通流量分配的标准。在蚁群优化算法的思想下,通过基于Ant-Cycle模型的容量限制分配方法,并对所测路网阻抗函数的参数重新进行了设定,从而对道路交通流量进行了分配。利用自编的基于软件MATLAB的蒙特卡罗程序求得容量限制分配前后的路面结构可靠度,进而求得对应的整个网络的结构可靠度。通过对上海市某一实际路网对比分析表明:路段拥堵时的容量限制分配尽管会提高相应路段的可靠度,但是被分配车流的道路可靠度会降低,进而最终的结果便是整个路网结构可靠度会降低。

The influence of traffic volume allocation due to limited capacity on the reliability of road network structure was analyzed in order to achieve the combination of the reliability of road network structure with the reliability of road network. The capacity reliability was achieved by traffic statistics and the capacity reliability of 0.4 was taken as criterion for traffic volume allocation. Based on the idea of ant-cycle algorithm and by method of traffic allocation due to capacity constraint and based on Ant-Cycle model, the parameter of impedance function of the road network under test was set anew for purpose of allocation of the road traffic volume. The reliabilities of pavement structure before and after allocation due to limited capacity were achieved by the self-prepared software of Monte Carlo MATLAB program to as to achieve the reliabity of corresponding whole network. The comparative analysis based on a real road network in Shanghai shows that although the reliability of related congested road section can be improved by means of traffic volume allocation according to limited capacity, the reliability of the road which received the allocation may decrease , which finally give rise to the reduced reliability of whole road network structure.