IIHS Explores Crash Injury Disparities in Men and Women

In frontal crashes, women were three times as likely as men to experience a moderate injury such as a broken bone or concussion and twice as likely to suffer a serious injury like a collapsed lung or traumatic brain injury, according to research conducted approximately one year ago by the Insurance Institute for Highway Safety (IIHS).

However, the researchers wanted to know how much of the gender discrepancy concerning crash injuries could be attributed to differences in the types of crashes men and women are involved in and the vehicles they drive. For example, men tend to drive bigger, heavier vehicles than women, and they are more likely to be behind the wheel in the striking, rather than the struck, vehicle in a side or front-to-rear crash.

So the team repeated the analysis with a narrower set of crashes, looking only at single-vehicle crashes and two-vehicle crashes in which the vehicles were a similar size and weight.

Noteworthy, in these crashes, women and men had similar odds of head and chest injuries — the types most likely to be fatal — but women remained twice as likely to suffer moderate injuries. The higher injury rates for women were primarily in the lower leg and foot.

The upshot is that the greater injuries in females versus males often comes down to differences in crash types and the interaction of different vehicle types and sizes. 

IIHS says improving safety for women can be addressed, but not simply with crash testing. Rather, researchers emphasize the use of technologies like automatic emergency braking, which is still absent from many of the heaviest passenger vehicles including pickups. Moreover, intelligent speed assistance (ISA) can either prevent speeding or issue warnings if speed limits are exceeded. Less speeding translates into fewer and less severe crashes.

Crash Dummies, Virtual Tests, Real-World Crashes

IIHS researchers are also assessing how to improve safety as is concerns the high rate of leg and foot injuries among women. Could using a female dummy in frontal crash tests help with that? 

Crash dummies are just crude representations of live humans — moreover, the first crash dummies were based solely on men’s bodies. Today they come in different sizes, representing men, children, and a very small (5th percentile) woman. The small female version has body dimensions and a pelvic design specific to women, but otherwise is largely based on the original, midsize male.

An updated version of the IIHS moderate overlap test that is planned for later this year uses a small female Hybrid III dummy in the rear seat, where its size could also represent a pre-teen child. But researchers say even as a stand-in for men, the Hybrid III dummy provides at best an approximation of how the body is affected by a crash. However, the dummy’s sensors record accelerations, forces, and deflections (e.g., how far a rib is pushed inward), and by comparing these measurements from many tests to injuries in many real-world crashes, IIHS is confidence in its ability to interpret the numbers.

When it comes to the lower leg and foot injuries that women disproportionately experience, the 50^th percentile Hybrid III dummy gives researchers some information, and it’s unlikely that a smaller, female version would reveal anything different. Newer, more sophisticated dummies with additional sensors have been developed and may someday provide deeper insights. But IIHS notes that no matter how sophisticated, a dummy is still just one dummy standing in for a diverse population.

Future tools for addressing women’s safety include virtual crash testing with computational modeling, according to IIHS. As a complement to physical tests, virtual tests can be conducted with an unlimited number of models representing the diversity of the human population. IIHS researchers also continue to study real-world crashes to bring different types of injuries and segments of the population into sharper focus.

A recent study from the National Highway Traffic Safety Administration (NHTSA) found that that crash injury disparities between men and women are much smaller in newer vehicles than in older ones. This indicates that the crashworthiness improvements of recent years have resulted in particularly big benefits to women.