Women are much more likely than men to suffer a serious injury when they are involved in a vehicle crash, which is primarily due to vehicle preferences and the circumstances of their crashes, according to new research from the Insurance Institute for Highway Safety. 

“The numbers indicate that women more often drive smaller, lighter cars and that they’re more likely than men to be driving the struck vehicle in side-impact and front-into-rear crashes” said Jessica Jermakian, IIHS vice president of vehicle research and one of the study’s authors. “Once you account for that, the difference in the odds of most injuries narrows dramatically.”

Though men are involved in more fatal crashes than women, on a per-crash basis women are 20-28% more likely than men to be killed and 37-73% more likely to be seriously injured after adjusting for speed and other factors, IIHS found.

One explanation of the higher injury rates for women could be vehicle choice, IIHS said. Around 70% of women crashed in cars, compared with about 60% of men. More than 20% of men crashed in pickups, compared with less than 5% of women. Within vehicle classes, men also tended to crash in heavier vehicles, which offer more protection in collisions.

Men and women crashed in minivans and SUVs in about equal proportions, IIHS found.

The researchers analyzed the injuries of men and women in police-reported tow-away front and side crashes from 1998-2015, IIHS said.

The IIHS studies also found women in front crashes were three times as likely to experience a moderate injury - such as a broken bone - and twice as likely to suffer a serious injury, IIHS found. Meanwhile, for side crashes, the odds of a moderate injury were about equal for men and women, though women were about 50% more likely to be seriously injured.

The researchers repeated the analysis with a limited set of “compatible” front crashes to determine how much of the discrepancy was due to physical differences between men and women, IIHS said.

This subset was restricted to single-vehicle crashes and two-vehicle crashes in which the vehicles were a similar size or weight or the crash configuration was such that a size or weight difference would not have played a big role, IIHS said. To further reduce differences among crashes, only those with a front airbag deployment were included.

However, IIHS researchers found that crashworthiness improvements have benefited men and women more or less equally, overall, when the institute limited the comparison to similar crashes between men and women.

“Our study shows that today’s crash testing programs have helped women as much as men,” said Jermakian. “That said, we found that women are substantially more likely to suffer leg injuries, which is something that will require more investigation.”

Recent research has also shown that serious and fatal injury risk has declined more for women than men as vehicles have gotten safer.

In a separate analysis of available data, researchers also found that in two-vehicle front-to-rear and front-to-side crashes, men are more likely to be driving the striking vehicle, IIHS said.

“The good news is that changes like strengthening the occupant compartment and improving seat belts and airbags have helped protect both men and women,” says Jermakian. “Homing in on the risk disparities that still exist in compatible crashes gives us a great opportunity to make further gains.”