Assessing the Impact of Road Infrastructure on Air Pollution: Evidence from Türkiye

Traffic-related air pollutants have significant impacts on urban air quality. Given the critical role of transportation infrastructure in shaping traffic congestion and vehicle emissions, understanding how road networks affect these air pollutants is particularly important in Türkiye, where rapid road expansion is a key component of transportation policy. This study examines the environmental implications of road infrastructure development in Türkiye by analyzing its impact on NO x emissions and PM 10 concentrations at the provincial level from 2012 to 2022. The dynamic panel results indicate that an increase in road length—including total roads, divided roads, and asphalt roads—significantly reduces NO x emissions, suggesting that expanded road networks may help alleviate air pollution by mitigating congestion and improving traffic flow. In contrast, no statistically significant relationship is found between road length and PM 10 concentrations, suggesting that particulate pollution is more strongly influenced by non-traffic sources such as industry, residential heating, or natural factors. By examining provincial road networks and differentiating between road types, this study provides novel evidence on the heterogeneous effects of road infrastructure on air quality, thereby addressing a significant gap in the existing literature and offering insights into how road infrastructure development influences environmental outcomes.