Temporal evolution and regional economic implications of the spatial structure of high-speed rail network in Western China’s urban agglomerations (2014–2024)

Abstract

Abstract During the development of transportation infrastructure in China, the high-speed rail (HSR) network has been rapidly expanded, exerting a substantial impact on regional economic growth. While most existing studies on the HSR-economy relationship have focused on developed regions in eastern China, this study selects two major urban agglomerations in the relatively less-developed western region—the Guanzhong Plain Urban Agglomeration (GPUA) and the Chengdu-Chongqing Urban Agglomeration (CCUA)—as its study subjects. This study constructs a multi-layer network framework based on complex network theory and the gravity model, incorporating physical and operational HSR networks along with an economic network. By employing Social Network Analysis (SNA), the Mantel test, and the Time Exponential Random Graph Model (TERGM), we systematically examine the spatiotemporal evolution of the HSR network structure, its correlation with the regional economic network, and the associated mechanisms and effects. The results indicate that from 2014 to 2024, the density of the HSR network increased in both the GPUA and the CCUA. The GPUA maintained a single-core structure centered on Xi’an, while the CCUA exhibited a dual-core structure with Chengdu and Chongqing as hubs. The Mantel test confirms a significant positive correlation between the HSR operational network and the economic network. This correlation is stronger in the more economically developed and administratively concentrated CCUA—spanning just one province and one municipality—than in the cross-provincial GPUA. Further analysis by TERGM demonstrates the independent role of HSR in the development of economic networks and its transmission path. Correlation analysis further reveals that enhanced HSR connectivity and strengthened economic ties are not fully synchronized.