Scheduling shared passenger and freight transport on a fixed infrastructure

As the number of deliveries continues to increase, last-mile transport causes rising congestion rates and pollution in urban environments. Integrating last-mile deliveries with existing public transport infrastructure, e.g., metros or trams, can make them more sustainable. This integration can implement in a shared infrastructure mode, where passenger and cargo vehicles share the same rail network, or a shared vehicle mode, where vehicles simultaneously transport cargo and passengers. Evaluating the resulting systems entails modelling several interlinking planning problems. This work presents a component-based simulation to evaluate design decisions for shared passenger and freight transport on fixed infrastructure. We introduce a linear mixed-integer program for optimising the train schedule and the allocation of cargo with a lexicographical objective function that prioritises passenger transport while minimising cargo delivery delay. We analyse the interplay of operational modes, scheduling solutions, and settings in a computational simulation study. The results show that a well-planned train schedule can significantly contribute to service quality. Furthermore, a system with shared vehicles is more robust towards changes in demand whereas a system with only shared an infrastructure is a valid option if we consider a high or unlimited dwell time for cargo vehicles.