This paper reviews three studies performed by the General Motors Research Laboratories which address different aspects of how age and sex affect injury rates in severe traffic crashes. All three studies use data from the Fatal Accident Reporting System, a file maintained by the National Highway Traffic Safety Administration. This data file gives information on all fatal traffic crashes in the United States occurring since January 1, 1975. The first study found relationships between risk of a fatality from the same physical impact and age and sex. The second study examined, as a function of sex and age, involvement rates in crashes in the same high severity range by combining the results of the first study with raw fatality rates in crashes. The third study included an examination of traffic fatalities relative to other causes of death. Almost half of all deaths to 18-year olds are due to traffic crashes. The studies reviewed provide additional focus on the large contribution of youth to traffic fatalities.