Rail express logistics network layout optimization model for E-commerce express delivery

The objective of this study is to solve the challenges of product allocation and network layout optimization in railroad express cargo transportation. This study aims to solve the railroad express transport problem, involving product distribution and network layout optimization. Therefore, this study considers three kinds of trains as carriers, which are dedicated express freight trains, high-speed rail (HSR) express freight trains, and standard express freight trains, based on which a mixed-integer nonlinear programming (MINLP) model is established to adjust the distribution of cargo flow and the transport routes of express trains by taking into account the constraints of the network capacity, route feasibility, and arrival time; meanwhile, the model optimizes the railroad network layout by upgrading the functions and grades of key nodes within the railroad network. To validate the effectiveness of the proposed model, a case study, involving ten cities in the Beijing-Tianjin-Hebei region, was conducted to construct a railroad express logistics network to evaluate the performance of the model.