Does air pollution affect traffic safety? Evidence from cities in China

Does air pollution influence traffic safety? To answer this question, this paper empirically investigates the nonlinear impact of air pollution on traffic mortality by employing a balanced panel dataset for 102 Chinese cities covering 2014–2018. Also, this paper then discusses the nonlinear mediation effects of air pollution on traffic safety to test the influential mechanism between these two variables. The following three conclusions are obtained. First, air pollution has a nonlinear impact on traffic safety: a 1 μg/m³ increase in the average annual concentration of PM2.5 could lead to a 0.0439 increase in traffic fatalities per one million people, but the negative impact of PM2.5 on air pollution will be reduced in the long run. Second, heterogeneity analysis indicates that the impact of air pollution on traffic safety in northern cities of China, cities with lower levels of economic development is more serious than that in other cities. Third, air pollution may affect traffic safety by reducing transport efficiency and affecting drivers’ physiological status and cognitive abilities.