Adaptive large neighborhood search for the two-echelon location routing problem with simultaneous pickup and delivery and parcel lockers

Last-mile delivery in urban areas faces challenges due to traffic congestion and difficult access, leading to increased costs. To address these issues, the literature has explored alternative strategies such as parcel lockers and network optimization. This research enhances the Two-Echelon Location Routing Problem with Simultaneous Pickup and Delivery (2E-LRPSPD) by integrating parcel lockers into the new 2E-LRPSPD-PL model. In this model the first echelon includes a single depot, open satellites, and parcel lockers, while the second echelon features routes from satellites to home service and parcel locker customers. We propose an Adaptive Large Neighborhood Search (ALNS) heuristic and compare its performance with the CPLEX solver. Results show that ALNS consistently finds high-quality solutions more quickly than CPLEX. Most importantly, integrating parcel lockers results in a significant reduction in total travel distance, up to 64%, demonstrating the effectiveness of this approach in improving operational efficiency and customer convenience in urban logistics.