Unraveling the Speed Limit Reduction-Traffic Crashes Relationship: Is it the Law or the Enforcement? The Case of Sao Paulo, Brazil

Resumo:

Road safety is an important target for policy action that has been receiving increasing attention in recent years. According to the World Health Organization, more than 1.25 million people die each year as a result of road traffic crashes, with more than 90 percent of road traffic deaths occurring in low and middle-income countries. Several cities worldwide have implemented throughout the years policies to implement reduced speed limit in urban areas. This study investigates the case of the speed limit reductions that took place in Sao Paulo, Brazil, between the years of 2014 and 2015. Through a difference-in-differences and event study approaches, we measure how much of the decline in accidents and deaths can be attributed to the implementation of lower speed limits, disentangling the speed limit reduction-traffic crashes relationship, through the investigation of the role speed cameras enforcement in this context.