Coordinated Optimization Of Responsive Feeder Transit Running Route And Scheduling In Low Demand Areas

With the continuous expansion of the urban scale,the low-density travel areas such as the new urban fringe area have only opened a very small number of fixed lines of buses due to the small number of bus trips and uneven temporal and spatial distribution.In addition,such low-density travel areas are far from the city center,and taxis rarely arrive due to high empty driving rate and long waiting time,so residents in such areas have difficulty in travelling by public transport.Responsive Feeder Transit(RFT),as a new way of bus travel,is an important means to solve the "first/last kilometer" problem of residents in low-density travel areas.Therefore,this paper takes the RFT system in low-density travel area as the research object,and the application scenario progresses from simple to complex,to study the coordination and optimization of RFT running route and scheduling.The research content of this paper is as follows:(1)In order to maximize the utility of RPT system,a route and scheduling coordination optimization model of RFT system with single transfer station was constructed based on two-stage method.In the first stage,the single transfer station route and scheduling scheme are coordinated and optimized only when reservation demand exists in the system.In the second stage,the real-time response strategy based on the insertion method is adopted to determine whether to respond to the real-time application of passengers immediately,and the follow-up route optimization model of the current running vehicles is constructed.According to the response of real-time demand application,the coordinated optimization model of the first stage is called to update the subsequent vehicle route and scheduling scheme.Then,an improved ant colony algorithm was designed to solve the coordinated optimization model.Finally,taking the road network around Shangshuangtang Station of Changsha Metro Line 1 as an example,an example is given,significantly improve the efficiency of processing the real-time demand of new passengers.(2)In order to minimize the total operating cost of the RFT system,a coordinated optimization model of single transfer station RFT route and scheduling for alone pick-up and delivery with segmentation speed was built based on the improved two-stage optimization method.The first stage,according to the requirements of passengers booking vehicle routing and scheduling scheme is determined,the second stage,considering the real time demand response strategy based on insertion method is just a local optimization method,at the same time in order to reduce the frequent adjustment and optimization of route,A real-time demand response strategy based on quantitative batch processing instead of real-time processing and a dynamic route update strategy based on global optimization are proposed.Then,the solution method of road travel time and shortest route under time-varying road network is described,and an adaptive genetic algorithm is designed to solve the coordinated optimization model.Finally,taking the road network around Shangshuangtang Station of Changsha Metro Line 1 as an example,an example is given.It significantly improves the service level of RFT and reduces the update frequency of vehicle running route.(3)According to the dynamic changes of passenger demand and road network,a rolling cycle scheduling strategy is designed.By dividing the scheduling period into several time segments with unequal duration,the dynamic problems are transformed into static problems to deal with.Then,a coordinated optimization model of route and scheduling for RFT system with multiple transfer station is constructed.Finally,the road network around Guangsheng Station and Luositang Station of Changsha Metro Line 3 is taken as an example to analyze the calculation.This paper conducts a comprehensive study on coordinated optimization of RFT routing and scheduling in different application scenarios,which is conducive to promoting the application process of RFT in China,and has certain practical significance for improving urban public transport system and solving the "first/last kilometer" travel problem of residents in low-density travel areas.