Where the rubber meets the road: Pavement damage reduces traffic safety and speed

Abstract

Road maintenance constitutes a significant component of transportation spending at all levels of government. Formulation of an efficient transportation infrastructure policy requires information about factors affecting road and traffic conditions. We generate the first causal evidence that decreasing pavement quality increases vehicle crash rates and decreases average speed. Results from parallel segment and instrumental variable models using spatially and temporally disaggregated data from Federal-Aid Highway System (FAHS) roads in California show statistically and economically significant increases in vehicle crash rates and decreases in average vehicle speed caused by road damage. These results produce a range of effect sizes that exceed those using standard road quality data. The results imply significant increases in social costs attributable to road damage.