Study on Modeling for Urban Underground Logistics System Networks Based on the two-echelon Location-routing Problem

Actively planning underground transportation space will be an important measure to address the surge in urban surface goods logistics. This paper takes the actual transportation and freight conditions in Xianlin area of Nanjing city, Jiangsu province, China as an example to model and solve the two-echelon location-routing problem (2E-LRP) of urban underground logistics system (ULS) networks. The variation in freight volume after optimizing two-echelon nodes can reflect the changes in congestion index in different regions, which is used to evaluate the validity of the model. Additionally, a hybrid heuristic algorithm combining genetic algorithm and neighborhood search is employed to solve the second-tier node location model. The results demonstrate that the model we constructed and the proposed algorithm not only achieve excellent optimization outcomes but also exhibit perfect convergence. Therefore, its can be applied to optimize modeling in other distribution systems as well.