RESEARCH & EVALUATION
Vehicle Safety Research
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.
| Title | Report |
|---|---|
Early Detection of Thermal Runaway With Advanced DiagnosticsThis research investigated early detection of safety risks of Li-ion battery packs in electric/hybrid vehicles. Early detection technologies included rapid electrochemical impedance spectroscopy, sensing of volatile organic compounds, and H2 gas sensing technology. These sensors were used to monitor cells and packs for failure markers. This research evaluates the warning times during overtemperature and overcharge tests. The results show rapid electrochemical impedance spectroscopy consistently warned earlier for the overtemperature tests. For the overcharge tests, volatile organic compound gas sensors provided an earlier warning. The H2 sensors consistently had the shortest warning time for both test types. |
DOT HS 813 671 |
An Evaluation of Light-Vehicle Automatic Emergency Brake System Responses to 2-Wheel Road UsersThe research in this report used three test scenarios to evaluate the automatic emergency braking (AEB) performance of four light vehicles when presented with a test surrogate designed to emulate a bicyclist or motorcyclist as the principal target vehicle (POV). Two motorcycle and two bicycle test surrogates, and two lateral overlaps per POV type, were used for each test scenario. Time-to-collision values at the onset of the test vehicle's forward collision warning and automatic braking initiated by the AEB systems are presented. |
DOT HS 813 758 |
Pedestrian Test Mannequin Radar Cross-section Repeatability EvaluationThis report documents the repeatability of measuring the radar cross-section of two pedestrian mannequin test surrogates designed to emulate an adult and a child pedestrian. The test methodology discusses using two measurement procedures from the International Organization for Standardization surrogate devices that aided in the calibration offset calculations and results. |
DOT HS 813 748 |
FMVSS Considerations for Vehicles With Automated Driving Systems: Volume 4This report, the fourth in the series, documents continuing work identifying unnecessary/unintended regulatory barriers to self-certification and compliance verification of innovative vehicle designs with automated driving systems that lack manually operated driving controls (steering wheel, brake pedal, etc.). It gives technical translation options of 23 FMVSS, including definitions included in 49 CFR Part 571 Subpart A, crash avoidance standards, focusing on braking and electronic stability control, and crashworthiness standards focusing on rear impact, platform lift systems, and consideration for unconventional seating. It also describes work performed developing related compliance test procedures for ADS-equipped vehicles, focusing on braking and ESC test methods for FMVSS Nos. 135 and 126; and a study of the heavy braking and ESC requirements associated with FMVSS Nos. 105, 121, and 136. |
DOT HS 813 755 |
Vehicle Headlamp Aim Angle Test Procedure and Tolerance ResearchThis report summarizes research conducted to support NHTSA’s response to requirements of the Infrastructure Investment and Jobs Act (IIJA) of 2021 to amend Federal Motor Vehicle Safety Standard No. 108 “to include performance-based standards for vehicle headlamp systems (A) to ensure that headlights are correctly aimed on the road; and (B) requiring those systems to be tested on-vehicle to account for headlight height and lighting performance.” This effort focused on determining a test procedure for measuring lower beam headlamp aim angle and gathering data to provide a basis for developing aim angle tolerance values for use in a new FMVSS No. 108 requirement. The research performed provide data from which an on-vehicle headlamp aim angle tolerance with consideration for headlamp mounting height could be asserted. |
DOT HS 813 759 |
Safety Implications of Potential Advanced Driver Assistance Systems Sensor DegradationThis project focused on understanding how degradations affect advanced driver assistance system perception sensor performance. The scope included cumulative and permanent or semi-permanent degradations of camera, radar, and lidar, based on a literature review and stakeholder interviews. It developed and demonstrated methods for developing and testing degradations and evaluating sensor response using static tests with various targets to enable repeatable evaluation of combinations of base materials and degradations. The results identified the degradations that most affected sensor performance and narrowed the degradation samples for component and vehicle testing. High, medium, and low levels of each degradation were tested. Camera, radar, and lidar sensors and a ground truth system were mounted on vehicles for simultaneous data collection in dynamic scenarios using a target vehicle. |
DOT HS 813 740 |
Assessment of Light-Vehicle ADAS Crash Avoidance Technologies in Response to 2-Wheeled Vehicles as Principal Other VehiclesThis project examines the characterization testing of automatic emergency braking and blind spot intervention (BSI) system performances when encountering a 2-wheeled vehicle in a rear-end crash or lane change crash scenario. Tests represented variations on the NHTSA crash imminent braking and BSI test procedures using bicycle and motorcycle surrogates as comparisons with passenger vehicle test devices. Variables included speed, lateral offset, position of 2-wheeled vehicle behind a passenger vehicle test device, and lighting conditions. Testing was conducted for 5 light vehicles representing a mix of body styles and sensor systems (both camera-only and camera-radar fusion). |
DOT HS 813 689 |
Parametric Study of Pre-Crash Vehicle Maneuvers and Occupant Safety Performance ResponseThis report addresses the influence of pre-crash vehicle maneuvers on the injury risks of front-passenger-seated occupants during a frontal crash. Seat position and occupant characteristics including anthropometry, sex, and age were included in the developed design of experiments. |
DOT HS 813 631 |
Vehicle Automatic Lower Beam Activation System Test Procedure DevelopmentThis report describes the development and testing of a draft test procedure confirming the performance of vehicle automatic activation systems for lower beam headlamps (a.k.a. low-beam headlights) that turn the lamps on and off based on ambient light level. A valid laboratory-based method was developed for simulating ambient sunlight coming from a realistic direction and measuring that ambient illumination at a vehicle’s exterior windshield surface. |
DOT HS 813 683 |
Lower Beam Headlighting System Performance On-Vehicle Test Procedure ExaminationThe 2021 Infrastructure Investment and Jobs Act amended FMVSS No. 108 to include performance-based standards for vehicle lower beam headlighting systems to ensure they are correctly aimed and tested on vehicles to account for lamp height and lighting performance. This report summarizes an effort to develop a test procedure that assesses performance of lower beam headlighting systems while the headlamps are installed on the vehicle. This research evaluated accuracy and repeatability of the candidate test procedure that was based on previous NHTSA work to create a test procedure for assessing lower beam headlighting system performance and work by UMTRI to assess performance-based FMVSS No. 108 test methods. Seven light motor vehicle headlighting systems were tested. The vehicle measured illuminance averaged 7 percent higher than the laboratory measured illuminance. Overall, this effort revealed the challenges of an on-vehicle measurement method compared to a lab-based method. |
DOT HS 813 702 |