Bi-level Programming Model to Solve Facility Configuration and Layout Problems in Railway Stations

The facility configuration and layout design of hub stations play an essential role in building a practical and cost-efficient hub station system. In general practice, bi-level programming models are implemented based on specific objectives and constraints. In this study, an upper-level model is used to solve the facility configuration problem, which is constructed based on the predetermined facility types to calculate the quantity of each facility by three objectives, including the number of passengers queueing in line, passengers' average waiting time in the queueing system and the cost of facilities. A genetic simulated annealing (GSA) algorithm based on the. -constraints method is presented to optimize the upper-level model. A lower-level model is used to solve the facility layout problem. An optimization solver, named CPLEX, is applied in the lower-level model to calculate the abscissas and ordinates of the facility location after determining the facility configuration in the upper-level model. A case study of the Lanzhou West station in Northern China is demonstrated to verify the efficiency of the optimal solution from the bi-level model by using a commercial pedestrian simulation software, MASSMOTION. This study reveals an innovative method for optimizing station facility configuration and layout by using the heuristic novel algorithm, a discrete event simulation technology and effective utilization of the Building Information Model (BIM) data.