It's Time to Bring Equity to Injury Risk

The latest generation of Anthropomorphic Test Devices is known as THOR

The latest generation of Anthropomorphic Test Devices is known as THOR - Test device for Human Occupant Restraint. There are two sizes, representing the 50th percentile male body and the 5th percentile female body - that provide safety engineers with a large target design range of the population. 

The THOR devices have been in development for over a decade. They represent a significant improvement on the 40 year old “Hybrid III” devices that were first regulated by NHTSA in 1990’s. In conjunction with safety institutions, regulators and OEMs, the THOR devices have been completely redesigned to deliver significantly improved biofidelic representations and have been instrumented with 150 digital sensors distributed in those parts of the body most vulnerable to injury.

The THOR 5th, unlike her predecessor the Hybrid III 5th, is not an adaptation of the male device. She has been designed specifically to address women’s unique physiology. Her 150 sensors are designed to help address those parts of the body where women have increased vulnerability to injury. 

• In the neck there are upgraded sensors, improved muscle representation and a greater bending shape to detect the exact stresses caused by the initial crash impact, as well as the subsequent deployment of airbags and the impact of seat belts and head rests.
• The device’s chest has a soft polyurethane breast to better test the positioning of shoulder seat belts on female subjects; four additional deflection sensors are used to detect the effect of the seat belt given women’s different seating position. 
• Pressure sensors have also been embedded in the chest and abdomen, two areas where females experience disproportionate injuries. Seat belts rest differently on a female chest, so to help understand the impact of seat belts on protection and injury, the chest sensors now detect multi-point deflection. One reason why women may be more prone to abdominal injuries than males is that they have comparatively less protective fat around their bellies.[30] THOR-05’s abdominal pressure sensors should provide valuable data testing that hypothesis.
• Her abdomen has a new molded design with embedded APTS sensors to support the assessment of abdominal lesions caused during crash tests by restraint systems.
• The pelvis - which is particularly vulnerable in side impact crashes - has been completely redesigned to better model the female pelvic bone geometry. 
• Her arms and legs have also been instrumented in the elbow, knee,  femur and foot. 

The Risk to Women

Today’s average American female is 5.4 inches shorter and 27 pounds lighter than the average male.[5] Among other effects, this means women sit closer to the steering wheel in order to reach the pedals, leaving them more vulnerable in side impact crashes. With shorter legs, women reaching for pedals are also 80% more likely than men to suffer severe leg injuries.[6] In technical terms, women are often “out of position” drivers, essentially piloting vehicles designed for men.[7]

But as Dr. Arbogast pointed out, height and weight measurements do not nearly describe the extent of differences between male and female bodies. Take, for instance, differences in neck musculature. Male necks are more muscular and have greater spinal column strength; female necks use less muscle mass to support heads that are nearly as large and heavy. This means women are significantly more prone to whiplash in an accident. A 2013 NHTSA study found that, relative to males of the same age, females in deadly crashes were 9.4% more likely to die as a result of neck injury.[8]

The gender bias in road safety is costing women their health. Just overone million injuries were sustained bywomen in 2018 (76% in the driver’s seat).[12] A 2019 study from the University of Virginia found that women are 73 percent more likely to be severely injured or die in a frontal crash than men.[13]

Tragically, gender bias in road safety is also costing women their lives. In 2018, 8,593 American women were killed in car crashes, a majority of them (61%) in the driver’s seat.[14] A 2013 NHTSA report found that female drivers and right front passengers wearing their seat belts are 17% to 18.5% more likely than their male counterparts to be killed in a crash, largely due to unbalanced safety standards such as the current crash test dummy measures.[15] These uneven odds mean that the death of up to 1,342 mothers, daughters, spouses, and loved ones could be prevented in one year alone. Using National Safety Council (NSC) estimates, these preventable tragedies translate to an economic cost of over $2 billion in 2018.[16] The non-economic costs are immeasurable.

But the fact that the Hybrid III is still the predominant dummy in use for testing today reflects a troublingly persistent and structural gender bias. As Caroline Criado-Perez writes in her book Invisible Women: Exposing Data Bias in a World Designed for Men, car safety tests reflect “the type of unthinking that conceives of humanity as almost exclusively male.”[18]

Automotive engineers who design for the safety of “standard” men also leave the elderly at higher risk for death and serious injury in crashes.[19] This is a growing population: by 2030, the UN expects over 25 percent of people in Europe and North America to be over 60.[20] Yet the Hybrid III does not reflect the posture, bone density, musculature, and overall physiology of older individuals. In 2018, there were 849 preventable fatalities among elderly drivers, at a preventable economic cost of about $1.5 billion. That year there were a total of 230,755 injuries to elderly drivers in the U.S., at an economic cost of almost $3 billion.[21] The NCAP is testing how younger, fitter people do in a car crash, not how older people fare.  

FOOTNOTES

[5] Fryar, Cheryl D., Deanna Kruszon-Moran, Qiuping Gu, and CynthiaL. Ogden. “Mean body weight, height, waist circumference, and body mass index among adults: United States, 1999–2000 through 2015–2016.” National Health Statistics Reports; no 122. Hyattsville, MD: National Center for Health Statistics, 2018. https://www.cdc.gov/nchs/data/nhsr/nhsr122-508.pdf.  

[6] “Cost of auto crashes & statistics.” Rocky Mountain Insurance Information Association (RMIIA), 2015. www.rmiia.org/auto/traffic_safety/Cost_of_crashes.asp.

[7] “Inclusive crash test dummies: Rethinking standards and reference models.” Gendered Innovations in Science, Health & Medicine, and Environment, Stanford University. http://genderedinnovations.stanford.edu/case-studies/crash.html#tabs-2.

[8] Kahane, Charles J. “Injury vulnerability and effectiveness of occupant protection technologies for older occupants and women.” Report No. DOT HS 811 766. Washington, DC: National Highway Traffic Safety Administration, 2013. https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/811766.   

[12] National Highway Transportation Safety Administration. “Crash Report Sampling System (CRSS).” Accessed March 2020. https://www.nhtsa.gov/crash-data-systems/crash-report-sampling-system.

[13] Forman, Jason, Gerald S. Poplin, C. Greg Shaw, Timothy L. McMurry, Kristin Schmidt, Joseph Ash, and Cecilia Sunnevang. “Automobile injury trends in the contemporary fleet: Belted occupants in frontal collisions.” Traffic Injury Prevention, 20:6, 607-612. 2019. https://www.tandfonline.com/doi/pdf/10.1080/15389588.2019.1630825?needAccess=true

[14] Id. NHTSA CRSS.

[15] Kahane, C. J. “Injury vulnerability and effectiveness of occupant protection technologies for older occupants and women.”(Report No. DOT HS 811 766). Washington, DC: National Highway Traffic Safety Administration, May 2013.

[16] National Highway Transportation Safety Administration. “Fatality Analysis Reporting System (FARS).” Accessed March 2020. https://www-fars.nhtsa.dot.gov/Main/index.aspx.

[18] Criado-Perez, Caroline. “The deadly truth about a world built for men - from stab vests to car crashes.” The Guardian, 23 Feb. 2019. Excerpted from Invisible Women: Exposing Data Bias in a World Designed for Men, by Caroline Criado Perez (Chatto & Windus). https://www.theguardian.com/lifeandstyle/2019/feb/23/truth-world-built-for-men-car-crashes.

[19] “Inclusive crash test dummies: Rethinking standards and reference models.” Gendered Innovations in Science, Health & Medicine, and Environment, Stanford University. http://genderedinnovations.stanford.edu/case-studies/crash.html#tabs-2.

[20] United Nations, Department of Economic and Social Affairs, Population Division. “Population 2030: Demographic challenges and opportunities for sustainable development planning” (ST/ESA/SER.A/389). 2015. https://www.un.org/en/development/desa/population/publications/pdf/trends/Population2030.pdf.

[21] Id. NHTSA FARS.