We present a flexible public transit network design model which optimizes a social access objective while guaranteeing that the system's costs and transit times remain within a preset margin of their current levels. The purpose of the model is to find a set of minor, immediate modifications to an existing bus network that can give more communities access to the chosen services while having a minimal impact on the current network's operator costs and user costs. Design decisions consist of reallocation of existing resources in order to adjust line frequencies and capacities. We present a hybrid tabu search/simulated annealing algorithm for the solution of this optimization-based model. As a case study we apply the model to the problem of improving equity of access to primary health care facilities in the Chicago metropolitan area. The results of the model suggest that it is possible to achieve better primary care access equity through reassignment of existing buses and implementation of express runs, while leaving overall service levels relatively unaffected.
翻译:我们提出了一个灵活的公交网络设计模式,优化社会接入目标,同时保证该系统的成本和过境时间保持在其目前水平的预设幅度之内,该模式的目的是找到一套小的、即时的修改办法,对现有公共汽车网络进行现有修改,使更多的社区能够获得所选择的服务,同时对目前网络的运营商成本和用户成本影响最小。设计决定包括重新分配现有资源,以调整线路频率和能力。我们为这一基于优化的模式的解决提供了一种混合的 tabu搜索/模拟肛门算法。作为案例研究,我们运用该模式来解决改善芝加哥大都会地区初级保健设施公平性的问题。该模型的结果表明,通过重新安排现有公共汽车和实行直线运行,实现更好的初级保健公平性是可能的,同时使总体服务水平相对不受影响。