Express Package Delivery Optimization Using Walkers, Cargo Tricycles and Delivery Trucks

Last-mile deliveries are an ongoing city logistics challenge faced by logistics service providers in urban areas. To achieve city logistics objectives of optimizing logistics considering efficiency, sustainability, congestion and safety objectives; heterogeneous fleets can be employed. Heterogeneous fleets recognize that, in dense centers, trucks do not always present the most time-efficient or economical delivery option, and that walkers and cargo bicycles can be efficient while reducing social and environmental impact. One courier company operating in Toronto maintains a fleet of standard delivery vehicles and a network of on-foot delivery personnel, and is considering adding cargo tricycles to its fleet. This sparks the question of how to solve the vehicle routing problem given multiple vehicle types and time windows (VRPMVTTW), which requires methods beyond the current state of research. This study advances the state of knowledge on the VRPMVTTW by revising and implementing a heuristic method for optimizing vehicle type and route selection. That implementation is applied to operational demand data serving over 1200 customer points for a downtown Toronto case study. Sensitivity analysis shows that cargo tricycles are the dominant vehicle type under various potential operating conditions, including variation of cargo tricycle speed, operating cost, purchase cost, amortized vehicle cost, and capacity. Additionally, spatial heterogeneity in mixed fleets indicates that multiple vehicle types may efficiently operate together from one depot. This case study finds that cargo tricycles can be part of an optimal multi-modal last-mile delivery network and should be further considered for implementation in downtown Toronto. The heuristic developed is applicable beyond the scope of this study, advancing the state of the VRPMVTTW for urban operations.