Injury Vulnerability and Effectiveness of Occupant Protection Technologies for Older Occupants and Women

Aging increases a person’s fragility (likelihood of injury given a physical insult) and frailty (chance of dying from a specific injury). Young adult females are more fragile than males of the same age, but later in life women are less frail than their male contemporaries. Double-pair-comparison and logistic regression analyses of 1975-2010 Fatality Analysis Reporting System (FARS), 1987-2007 Multiple cause of death file (MCOD), and 1988-2010 National Automotive Sampling System-Crashworthiness Data System (NASS-CDS) data allow quantifying the effects of aging and gender on fatality and injury risk and studying how trends have changed as vehicle-safety technologies developed. In crashes of cars and light trucks and vans (LTVs) of the past 50 model years, fatality risk increases as occupants age, given similar physical insults, by an average of 3.11 ± .08 percent per year that they age. Fatality risk is, on average, 17.0 ± 1.5 percent higher for a female than for a male of the same age (but more so for young adults and much less so for elderly occupants). The relative risk increases for aging and females may have both intensified slightly from vehicles of the 1960s up to about 1990 (even while safety improvements greatly reduced the absolute risk for men and women of all age groups); since then, the added risk for females has substantially diminished, probably to less than half, while the increase for aging may also have diminished, but by a much smaller amount. Abbreviated Injury Scale (AIS) ≥ 2 nonfatal-injury risk increases only by 1.58 ± .35 percent per year of aging, but it is 28.8 ± 6.0 percent higher for a female than for a male. Older occupants are susceptible to thoracic injuries, especially multiple rib fractures. Females are susceptible to neck and abdominal injuries and, at lower severity levels, highly susceptible to arm and leg fractures. Female drivers are especially vulnerable to leg fractures from toe-pan intrusion. All of the major occupant protection technologies in vehicles of recent model years have at least some benefit for adults of all age groups and of either gender; none of them are harmful for a particular age group or gender. Nevertheless, seat belts have been historically somewhat less effective for older occupants and female passengers, but more effective for female drivers. Frontal air bags are about equally effective across all ages; side air bags may be even more effective for older occupants than for young adults. Air bags and other non-belt protection technologies are helping females just as much and quite possibly even more than they protect males; this may have contributed to shrinking the historical risk increase for females relative to males of the same age.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Technical Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 349p

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Filing Info

  • Accession Number: 01483683
  • Record Type: Publication
  • Report/Paper Numbers: DOT HS 811 766
  • Created Date: Jun 11 2013 9:44AM