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Vehicle Safety


The Office of Vehicle Safety Research and supports U.S. DOT’s and NHTSA’s safety goals by conducting research and safety testing of motor vehicles and motor vehicle equipment. 

NHTSA’s recently published vehicle safety reports are listed chronologically below.

129 Results

Development of Discrete Size Measurement Methodologies for Motorcycle Helmets

FMVSS No. 218 defines the discrete size of a motorcycle helmet and requires it on the label; however, it does not specify how to measure the size. In addition, there is no standard procedure for determining the helmet positioning index (HPI) used to align the helmet on the headform for measurements and testing. This research developed procedures to determine HPI and to measure discrete size of motorcycle helmets. Four methods for measuring discrete size and one method for determining the HPI were developed and evaluated.

Sex-Based Differences in Odds of Motor Vehicle Crash Injury Outcomes

This study documented the relative odds of various motor vehicle crash injury outcomes for females versus males while considering a broad range of crash types, pre-crash and crash variables, and occupant demographics. Multivariable logistic regression models were developed for this purpose. Several studies have documented the relative risk or odds of injury and fatality for females versus males in motor vehicle crashes, but none have combined the National Automotive Sampling System–Crashworthiness Data System (NASS-CDS) and the Crash Investigation Sampling System (CISS). The results of this study suggest that increased or decreased odds of injury for females versus males is dependent on the type of injury outcome, the associated crash type, and other relevant independent variables significantly associated with the respective injury outcomes. In many cases, females were found to have significantly higher injury odds than males. However, females were found to be, more often, at significantly lower odds of injury as compared to males across the 300 models considered in this study. This study presents the most comprehensive view to date of the differential odds of various injury outcomes for females versus males when considering all crash data in NASS-CDS and CISS from case years 2000 to 2021. The findings can be used, in part, to focus future research and associated physical and virtual testing efforts towards addressing possible injury scenarios and crash types where discrepancies in injury odds exist for both sexes.

An Approach for the Selection and Description of Elements Used to Define Driving Scenarios – Part II

This research report studied the elements and properties used to describe driving scenarios and builds on two previous research reports in which five scenarios were chosen from human driving data and various proposed behavioral competencies for automated driving systems. A preliminary list of elements and properties used to uniquely describe the five driving scenarios was developed to help facilitate reproducible, repeatable, and traceable representation. The selected elements and their properties were focused on the ground truth scenario information. In this report six scenarios were selected from available driving databases, crash databases, and the behavioral competencies not covered in the previous research. These six scenarios were analyzed to consider expansion of the preliminary list of elements and properties that can be used to facilitate more complete descriptions of driving scenarios.

Vehicle Classification and Equipment Type Crash Data and Market Survey

NHTSA evaluates market trends and crash data to understand how FMVSS affect motor vehicle safety. This report describes a crash data and market survey of five vehicle and equipment categories that all have unique relevance in the FMVSS: (1) large passenger vehicles, trucks, and SUVs excluded from FMVSS No. 208 air bag requirements (Class 2B); (2) limousines over 10,000 lbs. GVWR; (3) “entertainer” buses and motor homes over 26,000 lbs. GVWR; (4) medium buses that carry 11 or more occupants; and (5) motorcycle helmets. A market survey was conducted for all five vehicle and equipment categories, while the crash data analysis was conducted only for Class 2B large passenger vehicles of GVWR 8,500 lbs. to 10,000 lbs.

Status of NHTSA’s Roof Ejection Mitigation Research

NHTSA is continuing its exploration of roof ejection mitigation that began following NHTSA’s issuance of Federal Motor Vehicle Safety Standard (FMVSS) No. 226, “Ejection Mitigation,” which sets requirements to reduce the likelihood of complete and partial ejections of occupants through side windows during rollovers or side impact crashes. Three more platforms were identified for testing at NHTSA’s Vehicle Research and Test Center. The Lincoln MKZ, which is a large outer slider with production and countermeasure Protec II panels, and prototype roof air curtain designs from Hyundai-Mobis and Autoliv.

A Modeling Study on Child Occupant Safety With Unconventional Seating Configurations

This study uses computer models to study how unconventional seating positions and orientations such as those conceptualized to be offered in vehicles with Automated Driving Systems may affect occupant response metrics of children restrained by child restraint systems (CRS) equipped with internal harnesses (CRS harness-restrained) or the vehicle lap-shoulder belt, with and without belt-positioning boosters. A total of 550 simulations were conducted with the CRABI 12MO in rear-facing CRS, the H33YO in both rear-facing and forward-facing CRS, the H36YO in a backless booster, and the H310YO with and without a booster across a range of conventional and unconventional seating locations and orientations under five impact directions and various CRS installation methods. This is the first study using different child ATDs and CRSs to investigate child occupant responses in a wide range of impact directions and seating orientations.

Head-Up Displays and Distraction Potential

Head-up displays (HUDs) present opportunities and challenges for mitigating driver distraction.  HUDs may improve safety by reducing the time required to view driving-related information relative to a traditional head-down displays (HDDs).  However, because the HUD is in the driver’s field of view, drivers may fixate on it or fail to perceive events in the environment. This study investigated driver use of a HUD, an HDD, and an aftermarket display by measuring visual behavior during public road driving.

Adaptive Driving Beam Headlighting Systems Rulemaking Support Testing

This report describes testing and analysis conducted to support resolution of NPRM comments about a compliance test procedure for adaptive driving beam (ADB) headlighting systems. NHTSA’s 2018 NPRM proposed to allow ADB on light vehicles in the United States and described a compliance test procedure based on full-vehicle in dynamic test scenarios performed on a test track. Testing involving NHTSA’s proposed ADB test procedure and SAE’s Surface Vehicle Recommended Practice J3069, Adaptive Driving Beam, provided data supporting resolution of test procedure related comments.. Dynamic illuminance measurements validated test procedure results for light source types; vehicle lower beam headlamp performance against ADB glare limit criteria; and whether ADB-equipped vehicles respond similarly when tested using the modified NHTSA test fixture versus a FMVSS-compliant vehicle. It was determined that a full-vehicle, dynamic performance test for ADB headlighting systems was suitable for FMVSS use and effective in determining whether an ADB headlighting system limits glare to other motorists to specified criteria.

Development of an Automated Wheelchair Tiedown Restraint System for Automated Vehicles

This report describes a project to develop an automated wheelchair tiedown and occupant restraint systems (WTORS) that could be safely and independently used in automated vehicles by people who remain seated in their wheelchairs for travel. The literature review focuses on topics relevant to safe, independent use of automated vehicles to people who use wheelchairs. Other chapters discuss initial strategies on design space, prototype concepts, computational modeling, volunteer assessment, dynamic testing, validating frontal and side impact wheelchair models, optimization of WTORS restraint systems, hardware development for the wheelchair attachments, vehicle anchorages, and automated belt donning arm, considerations for implementing usable wheelchair seating stations, hardware evaluation by eight volunteer wheelchair users, evaluation of prototypes in ten frontal and eight far-side impacts, and remaining challenges.

THOR-50M Repeatability And Reproducibility of Qualification Tests

This report documents NHTSA’s evaluation of the repeatability and reproducibility (R&R) of the 50th percentile Test Device for Human Occupant Restraint (THOR-50M) dummy in qualification tests. Repeatability (similarity of test responses from a single dummy when subjected to repeats of a given test condition) and reproducibility (similarity of test responses from several dummies when subjected to repeats of a given test condition) of the THOR-50M were evaluated by calculating the coefficient of variation values for each qualification test using several different dummies and test labs. With few exceptions, the results didn’t require a thorough review of the test procedures or necessitate the need for complete dummy inspections. Therefore, the THOR-50M R&R was deemed sufficient for use as a test tool for evaluating the safety of vehicles. Results obtained in a few tests identify areas for potential further investigation or provide opportunities to create future dummy enhancements.