Traffic congestion, transportation policies, and the performance of first responders

Traffic congestion is a growing problem in urbanizing economies that results in lost time, health problems from pollution, and contributes to the accumulation of greenhouse gas emissions. We examine a new external cost of traffic by estimating the relationship between traffic congestion and emergency response times. Matching traffic data at a fine spatial and temporal scale to incident report data from fire departments in California allows us to assign traffic immediately preceding an emergency. Our results show that traffic slows down fire trucks arriving at the scene of an emergency and increases the average monetary damages from fires. The effects are highly nonlinear; increases in response time are primarily due to traffic in the right tail of the traffic distribution. We document an additional externality of traffic congestion and highlight the negative effect of traffic on a critical public good.