Maria Weston Kuhn was left pondering a question about the car accident that led to her needing urgent surgery while on vacation in Ireland: How was it that she and her mother suffered serious injuries, whereas her father and brother, seated in the front, came away without a scratch?

“The crash was head-on, and they were closest to where the impact occurred,” said Kuhn, now 25, who had to take a semester off college to heal from the 2019 crash that caused her seat belt to slip off her hips, leading to a rupture of her intestines as they were pressed against her spine. “That was an initial hint that there was another factor at play.”

Upon returning to her home in Maine, Kuhn found a magazine article from Consumer Reports that her grandmother had clipped and left for her. She learned that women are 73% more likely to be hurt in a frontal crash, mainly because the crash test dummy used by the National Highway Traffic Safety Administration is based on a male body and dates back to the 1970s.

A survivor becomes an activist

Kuhn, who is starting law school at New York University this fall, took action and founded the nonprofit Drive US Forward. Its aim was to raise public awareness and eventually encourage members of Congress to sign onto a bill that would require NHTSA to incorporate a more advanced female dummy into its testing.

The agency has the final word on whether cars get pulled from the market, and the kind of dummy used in its safety tests could impact which ones receive coveted five-star ratings.

“It seems like we have an easy solution here where we can have crash test dummies that reflect an average woman as well as a man,” Sen. Deb Fischer, a Nebraska Republican who has introduced the legislation the past two sessions, told The Associated Press.

Senators from both parties have signed onto Fischer’s “She Drives Act,” and the transportation secretaries from the past two presidential administrations have expressed support for updating the rules.

But for various reasons, the push for new safety requirements has been moving at a sluggish pace. That’s particularly true in the U.S., where much of the research is happening and where around 40,000 people are killed each year in car crashes.

Evolution of a crash test dummy

The crash test dummy currently used in NHTSA five-star testing is called the Hybrid III, which was developed in 1978 and modeled after a 5-foot-9, 171-pound man (the average size in the 1970s but about 29 pounds lighter than today’s average). What’s known as the female dummy is essentially a much smaller version of the male model with a rubber jacket to represent breasts. It’s routinely tested in the passenger seat or the back seat but seldom in the driver’s seat, even though the majority of licensed drivers are women.

“What they didn’t do is design a crash test dummy that has all the sensors in the areas where a woman would be injured differently than a man,” said Christopher O’Connor, president and CEO of the Farmington Hills, Michigan-based Humanetics Group, which has spent more than a decade developing and refining one.

A female dummy from Humanetics equipped with all of the available sensors costs around $1 million, about twice the cost of the Hybrid used now.

But, O’Connor says, the more expensive dummy far more accurately reflects the anatomical differences between the sexes — including in the shape of the neck, collarbone, pelvis, and legs, which one NHTSA study found account for about 80% more injuries by women in a car crash compared to men.

Such physical dummies will always be needed for vehicle safety tests, and to verify the accuracy of virtual tests, O’Connor said.

Europe incorporated the more advanced male dummy developed by Humanetics’ engineers, the THOR 50M (based on a 50th percentile man), into its testing procedures soon after Kuhn’s 2019 crash in Ireland. Several other countries, including China and Japan, have adopted it as well.

But that model and the female version the company uses for comparison, the THOR 5F (based on a 5th percentile woman), have been met with skepticism from some American automakers who argue the more sophisticated devices may exaggerate injury risks and undercut the value of some safety features such as seat belts and airbags.

A debate over whether more sensors mean more safety

Bridget Walchesky, 19, had to be flown to a hospital, where she required eight surgeries over a month, after a 2022 crash near her home in Sheboygan, Wisconsin, that killed her friend, who was driving. While acknowledging the seat belt likely saved her life, Walchesky said some of the injuries — including her broken collarbone — were the result of it pinning her too tightly, which she views as something better safety testing focused on women could improve.

“Seat belts aren’t really built for bodies on females,” Walchesky said. “Some of my injuries, the way the force hit me, they were probably worsened.”

The Alliance for Automotive Innovation, an industry trade group, said in a statement to the AP that the better way to ensure safety — which it called its top priority — is through upgrades to the existing Hybrid dummy rather than mandating a new one.

“This can happen on a faster timeline and lead to quicker safety improvements than requiring NHTSA to adopt unproven crash test dummy technology,” the alliance said.

Humanetics’ THOR dummies received high marks in the vehicle safety agency’s early tests. Using cadavers from actual crashes to compare the results, NHTSA found they outperformed the existing Hybrid in predicting almost all injuries — including to the head, neck, shoulders, abdomen and legs.

A separate review by the Insurance Institute for Highway Safety, a research arm funded by auto insurers, was far more critical of the dummy’s ability to predict chest injuries in a frontal crash. Despite the vast expansion in the number of sensors, the insurance institute’s testing found, the male THOR dummy was less accurate than the current Hybrid dummies, which also had limitations.

“More isn’t necessarily better,” said Jessica Jermakian, senior vice president for vehicle research at IIHS. “You also have to be confident that the data is telling you the right things about how a real person would fare in that crash.”

The slow pace of changing the rules

NHTSA’s budget plan commits to developing the female THOR 5F version with the ultimate goal of incorporating it into the testing. But there could be a long wait considering the THOR’s male version adopted by other countries is still awaiting final approval in the U.S.

A 2023 report by the Government Accountability Office, which conducts research for Congress, cited numerous “missed milestones” in NHTSA’s development of various crash dummy enhancements — including in the THOR models.

Kuhn acknowledges being frustrated by the slow process of trying to change the regulations. She says she understands why there’s reluctance from auto companies if they fear being forced to make widespread design changes with more consideration for women’s safety.

“Fortunately, they have very skilled engineers and they’ll figure it out,” she said.