NHTSA Measures Bodies for Better Car Seat Safety
Published Date: 11/24/2025
Notice
Summary
The National Highway Traffic Safety Administration (NHTSA) is asking for approval to collect new info about how people’s body sizes and seating affect vehicle safety. This affects anyone involved in vehicle design and safety research, aiming to make cars safer and more comfortable. Comments on this plan are open until December 24, 2025, with no big costs expected for the public.
Analyzed Economic Effects
4 provisions identified: 2 benefits, 2 costs, 0 mixed.
NHTSA Will Update Body-Shape Data
NHTSA will collect new data on adult body size, shape, posture, and motion to update decades-old measurements used to design crash test dummies and human body models. The study will support development of anthropomorphic test devices (ATDs) and human body models (HBMs) and is not associated with immediate regulatory action.
Study Will Oversample High-BMI and Wide Size Range
The study will recruit adults across three age bins (20-39, 40-59, 60-80) and span statures from 1498 mm to 1875 mm, with BMI sampled in three bins so that about 50% of participants have BMI >30 kg/m2 and about one-sixth have BMI >40. Recruitment will oversample the tails to ensure robust statistical power.
Drivers Can Volunteer For Safety Study
If you are an English-speaking licensed driver age 18 or older in the Ann Arbor, MI region, you can volunteer for NHTSA's one-time study and will be compensated. NHTSA plans about 300 in-lab participants (100 per year) and 100 in-vehicle participants (about 34 per year); in-lab sessions take about 2 hours and the in-vehicle study takes about 2 hours (including a 100-minute drive).
Estimated Respondent Burden And Government Costs
NHTSA estimates 2,000 screening questionnaire responses (about 667 per year), 300 in-lab participants total (100 per year), and 100 in-vehicle participants total (about 34 per year). The agency estimates total burden of 1,017 hours (341 hours annually) and an annual opportunity cost to respondents of $11,329; government cost is estimated at $49,119.15 total and $16,373.05 annually.
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