Freight Flow Equilibrium Assignment on a Multimodal Transport Network Integrating Urban Roads and Passenger-Freight Metro Lines

In the context of metro-based freight, an equilibrium analysis framework is developed for freight demand within a multimodal transport network that integrates urban roads and passenger-freight metro lines. This framework specifically accounts for the impact of road freight-induced traffic congestion on car drivers, as well as the effect of in-train crowding caused by metro freight on metro passengers. Consequently, a freight flow equilibrium model with capacity constraints is proposed to address the freight flow assignment problem in such a multimodal network, and the augmented Lagrangian relaxation method is employed to solve it. A small-scale example is used to illustrate the details of the flow assignment process, while a set of large-scale examples demonstrate the computational efficiency of the algorithm. Finally, the resulting freight flow assignment is applied to assess the contribution of metro-based freight in reducing fuel consumption from urban road traffic.