Transport Infrastructure Development and Interregional Trade Flows: Evidence From Gansu Province

This study employs a county-level refined computable general equilibrium (CGE) model to analyze the impact of transportation infrastructure in Gansu Province on inter-regional trade and coordinated regional development. The results indicate that infrastructure improvements exert a positive influence on regional trade, with long-term gains significantly outweighing short-term effects. Importantly, these impacts are heterogeneous across both sectors and regions. In particular, trade flows in Gansu shift from short-term resource outflows to long-term internal agglomeration, with resources increasingly concentrating in more competitive areas within the province. In terms of road types, national highways facilitate the inflow of resources from other provinces, while provincial roads enhance intraprovincial circulation but exacerbate regional disparities. Finally, regarding the mechanisms of influence, investment-led growth, through capital accumulation and multiplier effects, emerges as the primary driver of economic expansion, surpassing the role of trade facilitation. Our findings provide valuable insights for local governments in making strategic decisions about transportation infrastructure investment.