RESEARCH & EVALUATION

Vehicle Safety Research

Vehicle Safety

Resources
Reports Library (rosap)

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.



139 Results
Title
 

Propagation Mitigation Testing Procedures, Modeling, and Analysis

This report explores propagation mitigation in packs of lithium ion pouch cells commonly used in large electric vehicles. Abuse tests were then used to initiate failure within a single cell in either the sub-assembly or pack. It developed a numerical model to capture damage propagation in lithium ion cells and modules in which thermal runaway is triggered using different initiation methods. The interplay of three parameters for passive thermal management on thermal runaway mitigation was numerically studied, including thermal mass of metallic inserts, thermal contact resistance between components, and cooling rate. Based on these results, it found that connecting metallic inserts between cells instead of using separate metallic inserts between cells is more helpful for thermal runaway mitigation since the former can take advantage of total thermal mass of metallic inserts, while the latter only of the thermal mass of individual metallic inserts next to the damaged cell.

 DOT HS 813 230

Event Data Recorder Duration Study Appendix to a Report to Congress

The EDR duration study was initiated in August 2016 and conducted by researchers at Virginia Tech over a 9-month period.  The research examined existing NHTSA crash investigation programs and naturalistic driving studies to provide bounds on the recording durations necessary to capture available driver inputs preceding a crash. This is the appendix for the report: Results of Event Data Recorders Pre-Crash Duration Study: A Report to Congress.

 DOT HS 813 082B

Results of Event Data Recorders Pre-Crash Duration Study: A Report to Congress

The EDR duration study was initiated in August 2016 and conducted by researchers at Virginia Tech over a 9-month period.  The research examined existing NHTSA crash investigation programs and naturalistic driving studies to provide bounds on the recording durations necessary to capture available driver inputs preceding a crash. This report provides the detailed results from that effort. It is accompanied by its appendix: Event Data Recorder Duration Study Appendix to a Report to Congress.

 DOT HS 813 082A

Comparison of the aPLI, FlexPLI With Upper Body Mass, and FlexPLI Pedestrian Legforms in Matched-Pair Vehicle Tests

Pedestrian knee ligament injuries and lower leg fractures are the most frequent and among the most debilitating long-term injuries in motor vehicle crashes. Global Technical Regulation No. 9, Pedestrian Safety, has been adopted by the international community to mitigate these pedestrian injuries through improved vehicle bumper systems. The current UN GTR includes the flexible pedestrian legform impactor (FlexPLI), which simulates the lower limb of a pedestrian and is the device widely used in global New Car Assessment Programs to assess the protection level of the front-end structures of vehicles. This study evaluated the upper body part addition to the FlexPLI (FlexPLI-UBM) and the advanced pedestrian legform impactor (aPLI) and compare vehicle test results with one another and with the current FlexPLI in matched impacts.

 DOT HS 813 086

WorldSID 50th Percentile Male Durability Assessment

This report documents the durability assessment of the WorldSID 50th percentile male dummy when exposed to severe test conditions. The dummy was subjected to component qualification tests conducted at elevated energy levels. Before and after completion of the elevated energy tests, the dummy was exposed to baseline energy levels to help assess possible changes in the dummy’s responses due to the elevated energy tests. Components of the dummy were also closely inspected after each test to determine if any damage occurred. This assessment demonstrated the dummy exhibits good durability.

 DOT HS 813 212

Enhanced Seat Belt Reminder Systems: An Observational Study Examining the Relationship With Seat Belt Use

Reducing motor vehicle crashes and injuries remain a priority for the highway safety community. Over 90 percent of drivers and front passengers use seat belts but about half of crash-related fatally injured occupants were unbelted. Motor vehicle manufacturers install seat belt reminder systems in compliance with FMVSS No. 208. The systems vary in audible sounds, instrument panel icons, text messages, intensity, and duration. Some exceed FMVSS No. 208 requirements and are recognized as enhanced seat belt reminder (ESBR) systems. This project examined effectiveness of various ESBR systems in promoting seat belt use among drivers and right-front seat passengers. Data collectors observed drivers and right-front seat passengers in 69,984 vehicles in 8 States and recorded age, gender, and belt use, vehicle type, and license plate number. State DMVs were able to provide data on 61,074 vehicles. Results showed a beneficial effect of combinations of sound, icon, and text elements; of extended periods of warning systems; and of systems compliant with European New Car Assessment Programme standards. The effectiveness of the presence and magnitude of specific ESBR systems are dependent upon whether the State has a primary seat belt use law.

 DOT HS 812 808

Classification of Level 2 Driving Automation Events Observed on Public Roads – Part 2

This report summarizes data collected while operating two passenger vehicles equipped with SAE level 2 driving automation systems on public roadways using three pre-established test routes.  Driver-annotated videos were used to document system operation during a variety of traffic scenarios.  Three classification types were used to categorize events (notable driving situations) observed during the drives.

 DOT HS 813 195

Assessing the Feasibility of Adding Additional Actors to Intersection Safety Assist Draft Test Scenarios

This report summarizes how variants of two test scenarios and three sub-scenarios, defined in NHTSA’s intersection safety assist draft research test procedure, assessed the feasibility of increasing the number of actors (e.g., other vehicles) in each driving situation. Better understanding the factors associated with such additions is of interest to NHTSA, as the expanded capability may improve its ability to research new or more complex real-world driving situations on the test track. Addition of another actor to the ISA scenarios increased the complexity of the tests, however not to the extent where it always and significantly affected overall burden. All test tolerances used to assess trial validity were satisfied for five of the six tests conditions described in this report.

 DOT HS 813 185

Assessing the Feasibility of Adding Additional Actors to Traffic Jam Assist Test Scenarios

This report summarizes how two traffic jam assist test scenarios were used to assess the feasibility of increasing the number of vehicles (actors) used for performance evaluations; a capability that may help NHTSA research new and/or more complex real-world driving situations on the test track. Generally speaking, the work described in this report indicates the incorporation of additional actors is possible, although some testing elements require further refinement, such as configuration settings used by the robotic controllers.

 DOT HS 813 169

Automated Driving Systems’ Communication of Intent With Shared Road Users

The three studies in this project explored shared road user need for information about Automated Driving System (ADS) vehicle intent and developed procedures to evaluate external human/machine interface concepts communicating intent of ADS vehicles. In Study 1 driving instructors determined visual and auditory cues most important for predicting the actions of drivers.  In Study 2 drivers, pedestrians, and bicyclists travelled on public roadways while verbally commenting about the actions of nearby vehicles. In Study 3 participants watched videos of an approaching vehicle with various evaluating external human/machine interface concepts superimposed. Results suggest shared road users seek out and use key pieces of information from vehicles. The results could inform human factors guidance regarding communication of intent for automated driving systems.

 DOT HS 813 148