A Time Geography Approach to Understanding the Impact of Gasoline Price Changes on Traffic Safety

Gas Prices and Crashes
Gas Prices and Crashes

Working paper:

The impact of gasoline price changes on traffic safety has received increasing attention in empirical studies. However, this important relationship has not been explained within a conceptual or theoretical framework. In this study, we examine this relationship within a time geography framework in an attempt to understand the effect of time-varying fluctuations in gasoline prices and their relationship to traffic safety in a case study of Mississippi from April 2004 to December 2008. We further extend this work by examining the degree to which this relationship is differential in impact by age, gender, and race. The results suggest that changes in gasoline prices have immediate effects on reducing total traffic crashes and crashes of younger drivers, women, and whites. However, changes in gasoline prices do not affect total crashes of older drivers, men, or blacks. Within the theoretical framework of time geography, we understand gasoline prices as one type of capability constraint of the space-time path and space- time prism. As gasoline prices increase (that is, as the capability constraint becomes stronger), traffic crash rates will decrease. However, the effects vary by age, gender, and race because the capability constraint of gasoline prices differs across demographic groups.