Optimal Locker Placement for Budget-Constrained Crowdshipping in Public Transport Networks

In this paper, we study the problem of optimally designing a sustainable crowdship-ping system integrated into the public transport network of an urban area, where commuters transfer parcels between lockers at public stations. We propose a bi-objective mixed-integer programming model that maximizes customer satisfaction and the number of stations equipped with lockers (network extension), accounting for both fixed and variable costs. The mathematical model allows computing the structure of an optimal crowdshipping system across various scenarios, varying in network size, shape, and daily commuter numbers. The results gathered running tens of thousands of simulations provide valuable managerial insights for logistics service providers that evaluating the feasibility and benefits of investing in crowdshipping networks.