The construction of urban transportation infrastructure is bound to have an impact on air pollution. The purpose of this paper is to verify whether strengthening the construction of urban transportation infrastructure can reduce haze pollution. The core innovation of this paper is that the fixed asset investment of urban municipal public facilities and urban road areas are used as the proxy indicator of transportation infrastructure, which is rarely adopted in the existing literature. The relationship between transportation infrastructure and haze pollution is discussed, and the endogenous problems caused by variables omission are also considered. Based on the panel data of 13 prefecture-level cities of Beijing-Tianjin-Hebei (BTH) region from 2005 to 2016, we use the slope index as the instrumental variable for urban transportation infrastructure, with the two-stage least squares method (2SLS) applied. The results suggest that: (i)increasing urban transportation infrastructure investment can significantly improve the air quality of the sample cities and mitigate haze pollution levels; (ii)After using the instrumental variable to alleviate endogenous bias, the inhibitory effect is more obvious; (iii)Compared with the fixed asset investment in the construction of public facilities, the increase of urban road area has a better effect on the improvement of haze pollution. What we learned from the conclusions is: traffic management department should strengthen the transportation infrastructure construction to realize the balance between urban construction and environmental protection.