The National Highway Traffic Safety Administration (NHTSA), part of the Department of Transportation, has published a notice in the Federal Register seeking approval for a new information collection under the Paperwork Reduction Act. Titled "Occupant Anthropometry and Seating," this effort targets updated data on adult body dimensions, postures, and movements in vehicle environments. Announced on November 24, 2025, the notice follows a 60-day comment period that ended with one submission, and it now opens a 30-day window for further input until December 24, 2025. The initiative responds to significant shifts in the U.S. population's body composition since the 1980s, alongside advancements in measurement technology and vehicle seating options. By gathering fresh anthropometric data, NHTSA aims to refine tools like crash test dummies and human body models, ultimately supporting better occupant protection in crashes. This development holds importance for vehicle safety research, as it could inform future standards without immediate regulatory ties.
Background and Rationale
The foundation for current anthropomorphic test devices (ATDs), often called crash test dummies, stems from a 1980s study by the University of Michigan Transportation Research Institute (UMTRI). That research, known as the Anthropometry of Motor Vehicle Occupants (AMVO), measured volunteers in seated positions to define specifications for small female, midsize male, and large male occupants. It targeted specific percentiles for stature and weight, such as the 5th percentile female and 95th percentile male. These data have underpinned most adult ATDs since then, but limitations persist. As the notice explains, "the current generation of ATDs is based on data gathered at UMTRI in the 1980s." Since that era, the U.S. population has seen a "large increase in body mass," rendering the old dataset obsolete. Measurement tools have evolved too, with three-dimensional surface scanners enabling more precise captures. Vehicle designs now feature greater recline angles, expanding beyond traditional postures.
NHTSA's notice highlights the need for this update, noting that "this combination of a population size shift and more variable seat configurations presents a clear need for updated seated anthropometry." The agency cites crash injury data showing higher risks for certain groups, such as elevated lower-extremity injuries for female drivers in frontal impacts and increased vulnerabilities for those with high body mass due to restraint interactions. Without new data, tools like human body models (HBMs) remain anchored to outdated or limited samples, often derived from single individuals rather than broad populations.
Study Design and Methodology
The proposed collection involves two main components: an in-lab study and a subset in-vehicle study, both approved by UMTRI's Institutional Review Board. Participants are licensed adult drivers aged 18 and older, recruited voluntarily with compensation. The process begins with an online screening questionnaire (NHTSA Form 1824) to assess eligibility, followed by phone confirmations (NHTSA Form 1825) and informed consent (NHTSA Form 1826). In the lab, measurements include manual anthropometry and 3D scans in various seating mockups, capturing dimensions like stature, weight, and joint locations as detailed in Tables 1 and 2 of the notice.
A subset proceeds to the in-vehicle phase, involving pre-drive (NHTSA Form 1827) and post-drive questionnaires (NHTSA Form 1848), additional consent (NHTSA Form 1828), and driving sessions. The notice specifies recruitment targets: stature from below the 5th to above the 95th percentile, body mass index (BMI) with half over 30 kg/m², and ages distributed across 20-39, 40-59, and 60-80 years. Seating conditions simulate diverse vehicle setups, including reclines up to 45 degrees. As the notice states, "posture will be measured using the FARO Arm at three seat back angles in each seat (20, 25, and 30 degrees) and at 35, 40, and 45 degrees for each participant in one randomly assigned seat."
This design incorporates advanced analysis, building on UMTRI's parametric modeling to generate specifications across sizes, unlike the averaging in AMVO. It also addresses belt routing and posture variations, using tools like VITUS laser scanners for 3D data processing.
Response to Public Comments
During the 60-day comment period, NHTSA received input from the Partnership for Dummy Technology and Biomechanics (PDB), which praised the intent to update anthropometric data. PDB suggested enhancements like ensuring population representation, including age factors, and measuring second-row positions. NHTSA responded by affirming its sampling matrix, which oversamples tails for robust modeling and distributes ages to fill prior gaps. While second-row seats are not directly included, the notice notes that "test conditions will incorporate fixed seat back angles typical of second- and third-row seats, including highly reclined conditions." Other recommendations, such as manual measurements matching AMVO landmarks and belt routing assessments, were integrated, as evidenced by the detailed measurement tables. However, NHTSA declined to restrict testing to mornings or add seat pressure distribution, citing practical constraints and minimal expected impact.
Burden and Implications
NHTSA estimates 2,000 total respondents for screening, yielding 300 in-lab and 100 in-vehicle participants over three years. Annual burden is 341 hours, with an opportunity cost of $11,329 based on Ann Arbor's average wage of $33.43 per hour. The government cost is $49,119.15 total. This reflects voluntary participation, with eligibility focused on English-speaking drivers without musculoskeletal issues.
From a broader perspective, the study could bridge gaps in safety research. Proponents might see it as essential for equitable protection, given disparities in injury risks by sex and body size. Critics could question the scope, as PDB did, urging more on rear seating or pressure data. Legally, it aligns with the Paperwork Reduction Act, requiring OMB approval to minimize public burden while ensuring data utility.
In summary, this information collection represents a targeted effort to modernize occupant data for crash safety advancements. Potential next steps include OMB review post-comment period, followed by data analysis to develop updated HBMs and ATDs. Ongoing debates may center on expanding to underrepresented groups or integrating emerging technologies, while challenges involve balancing comprehensive sampling with logistical feasibility. These trajectories could shape future vehicle safety policies and research priorities.
