Impact of transportation infrastructure upgrading on the rapid development of regional economy: A quasi-natural experiment based on the opening of high-speed railway

• High-speed rail significantly boosts regional economic growth. • Tourism development mediates the relationship between HSR and regional growth. • Local economic conditions enhance the positive impact of HSR on regional development. Using data spanning from 2004 to 2022 from urban centers across China, this study examines the relationship between high-speed railway (HSR) openings and regional economic advancement. Findings indicate that the deployment of HSRs markedly enhances regional economic growth. Mechanism analysis suggests that tourism development acts as a mediating factor between HSR openings and high-quality regional economic growth. Furthermore, this study identifies a moderating effect, demonstrating that local economic conditions can magnify the beneficial impact of HSR on regional economic advancement, with variations observed throughout China's eastern, central, and western regions.