This study is to empirically investigate the impact of urbanization through improving transportation infrastructure, reflected by introducing high-speed rail (HSR), on the regional development with the interaction of the socioeconomic factors reflected by industrial structure. An advanced quantitative tool named multi-period difference-in-differences (DID) method is applied. We find the impact of urbanization through HSR on regional development is mixed while interacting with industrial structure helps to explain heterogeneities of the impact. The more the industrial structure tends to be agricultural, the greater the negative impact of HSR opening on regional economic development; meanwhile, the more the industrial structure evolves to be service-oriented, the greater the positive impact of HSR. This study highlights the importance of the interaction between urban growth and socioeconomic factors, which would provides a reference for government and urban planners to make decisions on introducing HSR or improving transportation infrastructure.

The planning of urban transportation infrastructure and land-related policies has a significant impact on the living conditions of urban residents and socio-economic development, particularly in emerging economies. As urbanization continues to advance, Metropolitan Areas (MAs) have become crucial for achieving industrial coordination, functional complementarity between cities, and integrated regional development. Applying Social Network Analysis (SNA), the gravity model, and Quadratic Assignment Procedure (QAP) analysis, this study investigated the spatial-temporal distribution patterns of High-Speed Railway (HSR) networks and economic networks in MAs in China and the dynamic coupling relationship between these two networks. The findings revealed that, although core cities in the Yangtze River Delta MA in China exert varying degrees of radiation and driving effects on the economic development of surrounding cities, the overall development remains immature with a noticeable disequilibrium phenomenon. The coupling relationship between the HSR networks and the economic networks also differs significantly among different MAs. It is expected that the findings and suggestions of this study will contribute to the improvement of urban planning and governance and facilitate coordinated development between urban transportation infrastructure and the economy in emerging economies.