Optimization of Urban Rail Transit Connection Scheme for Evacuating Large Volumes of Arriving Railway Passengers

Urban rail transit (URT) is an essential mode of travel used for evacuating passengers from railway stations. To provide timely and safe connecting services for passengers arriving at railway hubs, it is recommended for URT operators to develop a coordinated connection scheme considering the periodic incoming volume of railway passengers. According to the fluctuation characteristics of the large passenger flows in railways, this paper presents a reasonable scheme for increasing the capacity of URT trains. First, a method for calculating the effective evacuation capacity of URT trains and determining the time range that should be optimized according to the transportation capacity matching degree is proposed. The dwell time and departure interval are taken as decision variables in this adjustment period. Two constraints are considered: capacity convergence and the maximum safe capacity of the platform. Based on the consideration of reserved capacity for subsequent sections, the objective is to optimize the degree of matching between the effective evacuation capacity of the URT and the transfer demand of the arriving railway passengers. A multi-objective nonlinear integer-programming model is established for the coordinated connection of URT trains with large passenger flows, and a solution process of a train connection scheme is designed that involves a genetic algorithm. Finally, the effectiveness of the proposed model and algorithm is analyzed and verified by considering the Shanghai Hongqiao Hub-a transfer station between a high-speed railway and URT-as an example.