The Impact of Highway Transportation Infrastructure on Carbon Emissions in the Yangtze River Delta Region

To address the increasingly severe issue of carbon dioxide emissions, the Chinese government has set dual carbon goals: achieving peak carbon emissions by 2030 and carbon neutrality by 2060. Studying the impact of highway transportation infrastructure on carbon emissions is crucial for achieving these dual carbon goals and promoting sustainable development. Using balanced panel data from 41 cities in the Yangtze River Delta region from 2006 to 2019, this paper empirically analyzed the relationship and mechanisms of highway transportation infrastructure’s impact on carbon emissions using fixed effects models, mediating effects models, and threshold effects models. The empirical results indicate: (1) there is a nonlinear inverted-U-shaped relationship between highway transportation infrastructure and carbon emissions; (2) highway transportation infrastructure indirectly affects carbon emissions through foreign direct investment as a mediating variable; (3) the threshold effect model verifies that the impact of highway transportation infrastructure on carbon emissions exhibits threshold effects based on green technological innovation and industrial structure upgrading. This study enriches the research content in related fields to some extent and provides specific policy recommendations for achieving carbon reduction goals and promoting sustainable development.