Identification of critical transportation cities in the multimodal transportation network of China

Critical transportation cities often have a disproportionate impact on the functioning of the transportation network, and identifying critical transportation cities may help improve the overall performance of the transportation network. In this study, critical transportation city identification in the multimodal transportation network of China is conducted. First, a directed weighted network that can express both the direction and strength of intercity links in China is constructed. Then, five indicators measuring node centrality are used to evaluate the importance of the nodes in the train network, bus network and flight network. Third, principal component analysis (PCA) is used to identify the critical transportation cities. Finally, the influencing factors of importance of transportation cities are quantitatively estimated by fitting the stepwise regression. The results show that (1) cities in North China, Central China, East China, and South China have higher comprehensive scores, while cities in Northeast China, Northwest China and Southwest China have lower scores; (2) provincial capital cities and some larger cities are generally the central transportation hubs of a region; and (3) the comprehensive score of Chinese cities is closely related to GDP, resident population, local general public budget expenditure, and loans of financial institutions at year end.