The optimisation of train operation schedule for passenger-freight mixed transportation in urban rail transit: a case study of Shanghai metro

As an innovative approach to easing megacity congestion and boosting transport efficiency, subway freight transportation can enhance rail utilisation, accelerate logistics, and reduce pollution. First, from the perspective of passenger and cargo safety, a model with the objective function of maximising cargo passage efficiency was constructed to derive the optimal path for cargo entry into the station. Then, targeting minimal enterprise costs, with hourly granularity, optimisation models for train operation plans were formulated under three modes: passenger-cargo co-compartment, passenger-cargo co-train with separate compartments, and dedicated freight trains, leveraging the estimated remaining cargo capacity and predicted demand along the routes. Finally, a case study on Shanghai Metro Line 9 was taken to demonstrate the proposed approach, it can effectively tap the remaining transport capacity of subways during specific time periods, lower enterprise costs, ensure efficient operation of passenger and freight flows, and alleviate urban traffic and environmental pressures.