Train Service Planning With The Cross-line Operation Mode In Urban Rail Transit Network

With the expansion of urban scale,urban rail transit operated in the single-line operation mode is faced with challenges such as frequent passenger transfer and excessive passenger flow pressure in transfer station,the improvement space of travel efficiency is limited.Cross-line operation under the trend of interconnection can effectively compensate for the lack of single-line operation.It can flexibly adjust the service planning to meet the demand of passenger flow,and reduce the number of passenger transfer,effectively improve the quality of travel services.In this paper,the urban rail transit train service planning under cross-line operation mode at flat peak period is studied.Firstly,based on the cross-line conditions,return station conditions and passenger demand,the generation method of cross-line routing alternative set is proposed.Subsequently,the optimization model of train service planning is constructed to reduce the total cost of the operation company and passengers,and improve the matching degree between passenger demand and operation service.The main research work is as follows:(1)A method for generating cross-line alternative sets is proposed.Firstly,according to the layout of transfer stations with cross-line operation condition and return stations,combined with the maximum number of cross-line,the initial cross-line routing alternative set is generated.Secondly,according to the five factors of the number of cross-line passenger flow,the proportion of cross-line passenger flow,the length of the route,the coincidence degree with the local routing and the rationality of the routing direction,the final cross-line routing alternative set is generated.(2)Based on the known OD requirements and cross-line routing alternative set,on the basis of determining each local routing,the optimization model of urban rail transit train service planning is constructed by taking the departure frequency of each local routing,whether to operate the alternative cross-line routing and the departure frequency of cross-line routing as decision variables,so as to reduce the total cost of operation company and passengers.In order to calculate the travel cost of passengers,the model takes the minimum number of passenger transfers and the shortest travel time as the principle,and considers the constraints of train load rate and line capacity to allocate OD passengers group to each routing.The genetic algorithm with elite retention strategy is designed to solve the model.(3)Five lines and 92 stations(including 4 cross-line stations)with cross-line operation conditions in Chongqing rail transit network are selected for case analysis.Compared with the single-line operation mode,the total cost of cross-line operation based on optimized model is reduced by 2.07%,and the number of transfer per passenger is reduced from 0.53 to 0.34,decreasing by 35.85 %.Under the premise of constant total passenger flow,when the proportion of cross-line passenger flow increases from 23% to 55%,the total cost of cross-line operation mode compared with the single-line operation mode is reduced from 0.43% to 3.77%.With the transfer penalty coefficient increased from 3.35 RMB / person to 5.36 RMB / person,the total cost of the cross-line operation mode compared with the single-line operation mode is increased from 1.55% to 2.91%,which proves that the cross-line operation advantage will be more prominent under the trend of higher passenger demand for travel service quality.