Synergising urban freight transportation in passenger-oriented transit corridors: An efficient Mixed-Integer Linear Programming approach

Amidst the escalating urban logistics challenges driven by e-commerce growth, synergising freight delivery within urban passenger transit has emerged as an innovative remedy. This approach optimises latent capacity, mitigating unsustainable e-commerce operations without necessitating costly infrastructure expansion; however, it introduces management issues to urban passenger transit operations. In this study, we formulated this problem as an integrated model that encompasses freight train scheduling, package allocation, and passenger train rescheduling with dynamic passenger demand. To address nonlinearity in constraints, a variety of linearisation techniques have been introduced, notably, a novel linear modelling approach tailored to dynamic passenger demand. These techniques facilitate the transformation of the model into a Mixed-Integer Linear Programming (MILP) framework, along with a warm start strategy. Experiments affirmed the feasibility of integrating freight during off-peak hours, with a marginal impact on passenger waiting times, while recognising the freight capacity limitations associated with the platforms.