Geographic Variations in Mortality from Motor Vehicle Crashes

Using a new technique to study the mortality associated with motor vehicle crashes, we calculated population-based death rates of occupants of motor vehicles during the period 1979 through 1981 and mapped them according to county for the 48 contiguous states of the United States. Mortality was highest in counties of low population density (r = -0.57; P<0.0001) and was also inversely correlated with per capita income (r = -0.23; P<0.0001). Death rates varied more than 100-fold; for example, Esmeralda County, Nevada, with 0.2 residents per square mile (2.6 km²), had a death rate of 558 per 100,000 population, as compared with Manhattan, New York, with 64,000 residents per square mile and a death rate of 2.5 per 100,000. Differences in road characteristics, travel speeds, seat-belt use, types of vehicles, and availability of emergency care may have been major contributors to these relations. (N Engl J Med 1987; 316:1384–7.) MOTOR vehicle crashes are the leading cause of death in the United States among persons 1 to 34 years of age.¹ Detailed geographic analyses of the mortality associated with such crashes have not been undertaken, despite the fact that county maps such as those showing cancer “hot spots” have contributed to our understanding of other important health problems and have helped to identify high-risk populations.² State maps reveal major regional variations in death rates related to motor vehicle crashes¹ but lack the specificity of analysis according to county. For example, in such states as New York, where much of the.