Decoding Spatial Patterns, City Roles, and Community Structures in Intercity Express Delivery Network

In the e-commerce era, express delivery networks (EDNs) play an increasingly important role in linking intercity production and consumption. Although many studies have examined their characteristics, most rely on express origin-destination (OD) connections and overlook actual transport routes. Using large-scale waybill data, this study constructs a routing-based EDN in China and examines its spatial patterns, city functions, and community structures. The results show that although both the OD network and the EDN are dense in the east and sparse in the west, their organizational forms differ significantly. Contrasting with the diamond structure of the OD network, the EDN exhibits a more hierarchical hub-spoke structure, where dominant flows form a polycentric radial pattern. By jointly considering outflow, inflow, and transit volumes, we observe clear spatial differentiation in city functions and classify cities into eight functional types. Community analysis further reveals substantial differences in internal structure and cross-community connectivity: high-volume communities tend to be more polycentric and better connected across communities, whereas low-volume communities show stronger local dependence. These findings highlight the importance of routing information for understanding the actual organization of EDNs and provide an empirical basis for optimizing hub planning, logistics provision, and regional coordination.