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.



138 Results
Title
 

Restraint Design for Obese Occupants: Obese GHBMC Model Modifications [Fourth of Four Parts]

Fourth of four parts. This study modifies the Global Human Body Models Consortium obesity models to improve their response relative the obese postmortem human surrogates in a series of tabletop belt tests. This study found that (1) submarining could be modeled by breaking boundary condition or large shear deformation in flesh; (2) detaching connection between the pelvis and surrounding flesh could release the boundary condition and therefore allow for submarining; (3) pulling hard with a denser mesh in the flesh could break the boundary between flesh and pelvis therefore leading to submarining; large shear deformation can be realized through using SPG particle to particle bond failure criteria; (4) tuned smooth particle Galerkin parameters worked well in the belt pull test simulation, recreating similar kinematics in the obese GHBMC model to the PMHS; and (5) the same set of tuned SPG parameter did not enable the obese GHBMC model submarining in the rear seat sled test simulation.

 DOT HS 813 540d

Restraint Design for Obese Occupants: Belt Pull Test Simulations Error Effects Modeling [Third of Four Parts]

Third of four parts. This task evaluates the Global Human Body Models Consortium obesity models with respect to the obese postmortem human surrogates test series of tabletop belt pull tests performed at the University of Virginia’s Center for Applied Biomechanics. Using a finite element model of the test fixtures, 3D drawings of the original test fixtures were obtained and meshed. To investigate whether the obesity model can show kinematics similar to the human surrogates, additional sensitivity studies were performed. The results showed that none of the implemented changes could lead the GHBMC obesity model to submarining.

 DOT HS 813 540c

Restraint Design for Obese Occupants: Rear-Seat Simulations [Second of Four Parts]

Second of four parts. This study evaluates the biofidelity of Global Human Body Modeling Consortium models of obese people by comparing their kinematics with obese postmortem human surrogates in frontal sled tests. Experimental tests with a robotic arm as well as an Instron machine were performed on the seat cushion and seat back foam to characterize the mechanical properties of the buck components. The seat, seat back, frame, and seat reinforcement structure were 3D- scanned, cleaned, and meshed. To investigate whether the model is capable of submarining, additional simulations (each with a modification to the model) were performed. The results showed that adding mass to the abdomen or removing the abdominal organs did not change the model’s behavior significantly.

 DOT HS 813 540b

Restraint Design for Obese Occupants [First of Four Parts]

This study evaluates the biofidelity of Global Human Body Modeling Consortium models of obese people by comparing their kinematics with obese postmortem human surrogates in frontal sled tests. It developed a finite element model to define accurate boundary conditions. Experimental tests with a robotic arm as well as an Instron machine were performed on the seat cushion and seat back foam to characterize the mechanical properties of the buck components. The seat, seat back, frame, and seat reinforcement structure were 3D- scanned, cleaned, and meshed. To investigate whether the model is capable of submarining, additional simulations (each with a modification to the model) were performed. The results showed that adding mass to the abdomen or removing the abdominal organs did not change the model’s behavior significantly.

 DOT HS 813 540a

Nighttime Seat Belt Enforcement: A How-To Guide and Case Study Summary

This how-to guide is an overview of best practices to conduct nighttime seat belt enforcement (NTSBE). It contains practical checklists for law enforcement agencies to consider when planning and implementing NTSBE operations. In addition, this report describes NTSBE practices of case study states.

 DOT HS 813 537

Crash Compatibility for Occupantless Delivery Vehicles

This research studied how variations in an occupantless delivery vehicle’s (ODV) design can affect the occupants in an occupied crash partner vehicle, across a range of expected operational design domains. In full frontal and frontal oblique impact configurations, improved ODV compatibility correlated well with less severe LPV crash pulses, lower occupant compartment intrusions, and lower occupant injury risk for all four ODV categories. Optimized ODV frontal stiffness characteristics and reduced ODV vehicle mass correlated with improved compatibility and reduced crash partner occupant and structural loads. In side impacts, improved ODV compatibility also correlated with less LPV structural damage and lower occupant injury risk for three of the four ODV categories. Large and tall ODV with a more compatible lower frontal structure and a relatively stiff upper frontal structure produced higher roof deformation and higher head injury risk in the crash partner LPVs.

 DOT HS 813 332

Vehicle Assessment Using Integrated Crash Avoidance and Crashworthiness Pedestrian Safety Test Procedures

The objective of this study was to test a set of vehicles using both pedestrian automatic emergency braking (PAEB) and crashworthiness (CW) test protocols to evaluate ways in which the results of each test condition can be used to inform and, if necessary, refine, the test conditions and/or performance requirements of the other. PAEB test track results were used to determine CW head and leg impact speeds and locations, and CW test results were used to help understand minimum speed reduction requirements for PAEB tests. Secondary goals of this study were to explore a method for evaluating contact-induced safety features (i.e., deployable hood systems) and provide an improved overall picture of a vehicle’s expected real-world performance.

 DOT HS 813 521

Pedestrian Safety: Assessment of Crashworthiness Test Procedures

The objective of this study was to use finite element pedestrian and vehicle models to evaluate pedestrian interactions with vehicles equipped with pop-up hoods. A virtual database of pedestrian impacts was generated with a wide range of vehicle front-end geometries. Prediction models were developed for pedestrian head impact time (HIT), which is important to evaluate the response time of pop-up hood designs. Effects of pop-up hood design parameters on pedestrian head injury responses were ultimately investigated. Generic vehicle models used in Euro NCAP were morphed into 20 U.S. vehicle front-end geometries. A total of 240 pedestrian impact simulations were conducted using the morphed GV models with four sizes of pedestrian human body models at three impact speeds. A set of predictors were selected based on the literature to predict HIT, head contact velocity, and head contact angle. Simulations with the pop-up hood design found that a deployed hood could potentially collapse due to the kinetic energy of a pedestrian. Among the selected design parameters, actuator stiffness was the biggest contributor to avoiding collapse. Due to variations in kinetic energy provided by different size pedestrians, the deployment system of a pop-up hood needs to be designed for the highest pedestrian stature to avoid hood collapse. With deployment system design as per the highest pedestrian stature, the head injury criterion for a smaller pedestrian may slightly increase but is still lower compared to an undeployed hood for the vehicle used in this study.

 DOT HS 813 518

Pilot Study of Driver Use of A Camera-Based Visibility System Versus Mirrors

This report describes research on camera-based visibility systems, also referred to as camera-monitor systems (CMSs), and whether they can be used as safely as existing Federal Motor Vehicle Safety Standard No. 111 compliant outside rearview mirrors. CMSs are designed to be either a supplementary or alternative means to provide drivers with the rearward field of view currently afforded by mirrors. To address research questions in NHTSA’s Advance Notice of Proposed Rulemaking regarding whether CMSs have the ability to provide equivalent information to and ease of use as rearview mirrors, a human subjects experiment was performed examining drivers’ eye gaze behavior and driving performance in a light vehicle with rearview mirrors versus a prototype CMS.

 DOT HS 813 483

Assessment of Headlamp Aim for New Vehicles

This report summarizes an evaluation of new vehicle headlamp vertical aim angle state, or how well a new vehicle’s headlamps are aimed at the time of vehicle delivery to the purchaser. Using the inspection method from SAE J599 determined the vertical headlamp aim angle for a set of 15 vehicles. This procedure involves shining the lower beam headlamps at a screen and determining the location of the gradient cutoff location. The headlamp aim was measured for both passenger and driver side headlamps. Vehicles’ lower beam headlamp vertical aim angle was determined both with the vehicle was empty (no load) and loaded with weight to simulate a person in the driver seat (driver load). Headlamp aim was then judged based on the limits specified in SAE J599 as well as the manufacturers’ specifications for both test conditions.

 DOT HS 813 481