考虑混合车型模式的地铁接驳公交优化研究

Optimization of Feeder Bus Network with Multiple Vehicle Types for Metro Station

为提高地铁站周边区域乘客的出行便利度,研究地铁接驳公交线网规划问题,提出了两阶段优化方法。第一阶段基于动态规划和分支定界法思路生成满足约束的候选线路集合,第二阶段以乘客和运营单位综合成本最小为目标,以是否选择候选线路、线路发车频率和配属车型为决策变量,建立混合整数非线性规划模型,并设计定制化遗传算法求解。长沙月亮岛西地铁站案例表明,相比单一车型模式和公交站点仅允许单线接驳等既有方法,该方法可有效均衡各站满载率水平,总发车次数减少19.1%、服务车站覆盖率由45.5%提升至97%、目标函数优化率超过25%;设定接驳公交线路数量时应考虑覆盖更多站点和客流,减少未被覆盖的客流惩罚,但线路数量也不宜过大,否则会导致综合成本增加。因此,地铁接驳公交宜采用混合车型模式和允许站点被多线接驳,以适应不同客流需求、满足城市道路属性要求、丰富公交开行线路等,同时线路数量设定需权衡覆盖客流量和运营成本。

To improve transportation convenience of the area surrounding subway stations,the feeder bus network design around subway station was studied and a two-stage optimization method was proposed.The first stage was to generate the set of candidate bus lines which satisfy all the constraints based on the thought of dynamic programming and branch and bound method.The second stage established a MINLP(Mixed Integer Nonlinear Programming)model to minimize the comprehensive cost of passengers and companies.The decision variables of the second stage were the candidate lines,the departure frequency and vehicle types.Acustomized genetic algorithm was designed to solve the proposedMINLP model.The results of the case study of Yueliangdaoxi Subway Station in Changsha showed that the proposed model was able to balance the load rate of passengers across stations effectively.As a result,the frequency of feeder bus was reduced by 19.1%,the number of service bus stations was expanded from 45.5%to 97%,and the objectives were optimized exceeded 25%compared with two previous methods which own single vehicle type and each station could be served by only one bus line.In addition,the number of feeder bus lines needs be set to cover more stations and passengers so that the penalty of passenger which was not serviced could be reduced.However,it is not advisable to set too large a number of feeder bus lines,or the comprehensive cost may increase.Therefore,the feeder bus should adopt multiple vehicle types and allow the bus station to be connected by multiple lines so as to meet different passenger flow demands and the requirements of road attributes,enrich bus routes,etc.At the same time,the number of bus lines needs to balance the passenger demand and operating cost.