Since 1975, the US has seen a decrease in vehicle crash fatalities, noticeably among recent model vehicles. However, a lack of requirement to test motor vehicles using anthropomorphic test devices representative of both the average male and the average female occupant may be driving a disparity in the risk of fatality in severe crash scenarios. The double pair comparison method, first developed by Evans, was applied to many different cross-sections of the US Fatality Analysis Reporting System to investigate sex-dependent differences in relative fatality risk in crashes. Despite a dramatic decline in fatalities over the reporting period, female vehicle occupants aged 20–30 years are 20–25% more likely to die as a result of a fatal crash than males in the same age range. The risk to females and males becomes similar as age increases to 60. These trends hold when looking at subsets of crashes in either rural or urban areas, when looking at vehicles manufactured since 2010, and when isolating by single, two- or multiple-vehicle crashes. The consistency of this age-dependent relative risk emphasises a need to further investigate sex differences in crash-related outcomes.