An assessment of the rural-urban differences in the crash response time and county-level crash fatalities in the United States

Purpose This study aimed to estimate the crash response times in rural and urban counties in the United States, their association with county-level crash fatalities, and identify spatial clusters of crash fatalities across the United States. Methods We analyzed data from the Fatality Analysis Reporting System (2010-2019). Data were aggregated at the county level across the contiguous United States. The selected counties (n = 3,108) were categorized as rural, micropolitan-urban, or metropolitan-urban using the 2013 rural-urban commuting area codes. The predictor variable was crash response time, and the outcome variable was county-level crash fatalities. Crash and county characteristics were used as potential confounders. We performed a spatial negative binomial regression analysis and reported the rate ratios of crash fatalities. We estimated the crude and adjusted fatality rates across all counties and identified clusters of crash fatalities across the United States. Findings As one migrates from urban to rural areas, crash response times became significantly increasingly longer. The Emergency Medical Service (EMS) notification to scene arrival time was most predictive of crash fatalities. A minute increase in the EMS notification to scene arrival time was associated with a 1%, 2%, and 5% increased fatality rate ratio in rural, micropolitan-urban, and metropolitan-urban counties, respectively. Although crash fatalities were lower in rural counties, the crash fatality rate was 3-fold higher in rural counties compared to metropolitan-urban counties. Significant clusters of crash fatality rates were heterogeneously distributed across the United States. Conclusion Reducing crash response time may contribute to reducing crash fatalities across the United States.