Key nodes identification of multimodal transport in Northwest China using complex network theory

With the continuous expansion of the transportation network, it exhibits the characteristics of a complex network. Applying complex network theory to identify key nodes in transportation networks can provide a new perspective for the development, construction, and planning adjustments of these networks. Based on the structural characteristics of the road-rail-air network in the northwest region, a multimodal freight transportation network has been established. Evaluation indicators such as degree centrality, betweenness centrality, closeness centrality, freight volume, transfer and reloading equipment capacity, and tertiary industry GDP have been selected to construct a comprehensive evaluation system for node importance. Two comprehensive evaluation methods, random forest and grey relational analysis, have been employed to calculate and rank the comprehensive importance of nodes. The network is simulated to attack and analyze the trend of network performance changes to verify the key nodes. Finally, Xi'an, Urumqi, and Lanzhou are identified as the key node cities in the multimodal freight transport network in Northwest China.