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A database derived from information obtained in state police accident reports has been developed to support problem identification and counter-measure development in crash avoidance research. This database is sufficient in size to permit analyses of the relationship between specific vehicle design characteristics and crash involvement. Preliminary analyses of this database suggest that is is comparable with the nation's crash experience.

A review was conducted of injuries associated with ejection through motor vehicle glazing, using the 1988 through 1991 National Accident Sampling System data maintained by the National Highway Traffic Safety Administration. The review indicated that one percent of the occupants in towaway crashes were ejected and that 22 percent of fatalities in towaway crashes were ejected. Fifty-three percent of complete ejections were through the glazing openings in motor vehicles. Current motor vehicle glazing does not contribute significantly to occupant injuries, but the effects of glazing changes on serious injuries will need to be considered.

This paper presents the methodology and results of an analysis of the available information on motor vehicle safety which could be used to provide a basis for establishing priorities for future Government and private sector efforts directed at enhanced crash protection. The work was stimulated by several factors: (1) 5 years have elapsed since the National Highway Traffic Safety Administration (NHTSA) published a plan for motor vehicle safety research and development, (2) motor vehicles have changed substantially over the past several years, (3) the quantity and quality of accident data and vehicle crash performance information have increased dramatically over the past 5 years, and (4) Government policies and the amount of Government and private sector resources available for future efforts are changing.

This report documents the accident data collection, processing and analysis methodology used by the National Highway Traffic Safety Administration (NHTSA) in a major agency agency investigation of the rollover propensity of light duty vehicles. Specifically, these efforts were initiated in response to two petitions for rulemaking requesting the development of a standard for rollover stability. Logistic regression models were used to investigate the ability of a number of stability measures to predict vehicle rollover propensity, while accounting for a number of driver and environmental factors. It is not the intent of this paper to document formal agency policy in the area of any possible rulemaking efforts, and as such, references to these activities are not discussed. The reader can obtain information on this activity through normal agency procedures.

The National Highway Traffic Safety Administration and the University of Michigan Transportation Institute are investigating truck design countermeasures to provide safety benefits during collisions with light vehicles. The goal is to identify approaches that would best balance costs and benefits. This paper outlines the first phase of this study, an analysis of two-vehicle, truck/light vehicle crashes from 1996 through 1998 using several crash data bases to obtain a current description and determine the scope of the aggressivity problem. Truck fronts account for 60% of light vehicle fatalities in collisions with trucks. Collision with the front of a truck carries the highest probability of fatal (K) or incapacitating (A) injury. Truck sides account for about the same number of K and A-injuries combined as truck fronts, though injury probability is substantially lower than in crashes involving the front of a truck.

The NHTSA has developed automotive recorders which can measure crash triaxial acceleration/time histories during vehicle collisions. From these acceleration histories (recorded on a magnetic disc), velocity/time histories and velocity change during impact are derived to provide measures of vehicle crash severity. The purpose of developing these recorders is to provide accurate and quantitative relationships of vehicle crash severity with occupant fatalities and serious injuries from real-world accidents. To date, a total of 1200 disc recorders has been produced, approximately 1050 recorders have been installed in fleet vehicles, and 23 accident records have been analyzed. This paper has been prepared to present the progress made in the Disc Recorder Pilot Project as of March 31, 1974. Recorder data from accidents involving vehicles equipped with disc recorders will be discussed and compared with associated reports by accident investigators.

This paper focuses on the overall structure of the Crash Injury Research and Engineering Network (CIREN), how data are collected, and what makes it unique. It discusses how it can be used to expand and enhance the information in other databases. CIREN is a collaborative effort to conduct research on crashes and injuries at nine Level 1 Trauma Centers which are linked by a computer network. Researchers can review data and share expertise, which will lead to a better understanding of crash injury mechanisms and the design of safer vehicles. CIREN data are being used in outreach and education programs on motor vehicle safety. CIREN outreach and education has already been credited with lifesaving information dissemination.

This paper presents the details of the model for the physical steering system used on the National Advanced Driving Simulator. The system is basically a hardware-in-the-loop (steering feedback motor and controls) steering system coupled with the core vehicle dynamics of the simulator. The system's torque control uses cascaded position and velocity feedback and is controlled to provide steering feedback with variable stiffness and dynamic properties. The reference model, which calculates the desired value of the torque, is made of power steering torque, damping function torque, torque from tires, locking limit torque, and driver input torque. The model also provides a unique steering dead-band function that is important for on-center feel. A Simulink model of the hardware/software is presented and analysis of the simulator steering system is provided.

A major focus of the National Highway Traffic Safety Administration's (NHTSA) vehicle compatibility and aggressivity research program is the development of a laboratory test procedure to evaluate compatibility. This paper is written to explain the associated goals, issues, and design considerations and to review the preliminary results from this ongoing research program. One of NHTSA's activities supporting the development of a test procedure involves investigating the use of an mobile deformable barrier (MDB) into vehicle test to evaluate both the self-protection (crashworthiness) and the partner-protection (compatibility) of the subject vehicle. For this development, the MDB is intended to represent the median or expected crash partner. This representiveness includes such vehicle characteristics as weight, size, and frontal stiffness. This paper presents distributions of vehicle measurements based on 1996 fleet registration data.

This paper presents an approach for evaluating the effects of brake system component degradation on vehicle braking performance. The approach involves the use of an inertial brake dynamometer, vehicle computer simulation, and vehicle test. The approach, procedures, and results of the study of the effects of worn friction materials, worn discs and drums, and contaminated brakes are presented.

A comprehensive review of casualty-reducing effectiveness estimates of child safety seats in actual use, obtained by statistical analyses of highway accident data. Recent analyses of large samples of New York and Maryland accidents show statistically significant injury reductions for child safety seats; so does a new analysis of the National Highway Traffic Safety Administration's accident files. Results from Washington State, Tennessee, New Jersey, and Idaho are also reviewed, as are Nationwide restraint usage and fatality trends. The findings are critically examined for possible data biases. It is concluded that child safety seats definitely reduce deaths and injuries in highway crashes, but that their effectiveness cannot be accurately estimated at this time because of inconsistencies and possible biases in the various studies.

The objectives of this study were to develop and apply procedures for defining pedestrian safety zones for the older (age 65+) adult and to develop, implement and evaluate a countermeasure program in the defined zones. Zone definition procedures were applied to two cities: Phoenix and Chicago. Extensive countermeasure programs were implemented in both cities. A complete crash-based evaluation was conducted only for the city of Phoenix where data showed significant reductions in zone crashes to 65+ pedestrians over a period in which the city's population and overall pedestrian crashes increased. It was concluded that the zone process resulted in an effective and efficient means of deploying pedestrian countermeasures for the older adult.

Early influences upon Thor ATD development are described, and the path of Thor development is traced up to the release of the current Thor ALPHA ATD design. Since the display of the first Thor ATD prototype at the 15th ESV Conference in Melbourne in 1996, Thor has undergone extensive test and evaluation on an international basis in cooperation with many partner institutions. This paper summarizes some of the lessons learned from this broad test experience, and documents actions which have been undertaken to upgrade the Thor product to ALPHA status in light of this experience.

This study evaluated the response of restrained post-mortem human subjects (PMHS) in 40 km/h frontal sled tests. Eight male PMHS were restrained on a rigid planar seat by a custom 3-point shoulder and lap belt. A video motion tracking system measured three-dimensional trajectories of multiple skeletal sites on the torso allowing quantification of ribcage deformation. Anterior and superior displacement of the lower ribcage may have contributed to sternal fractures occurring early in the event, at displacement levels below those typically considered injurious, suggesting that fracture risk is not fully described by traditional definitions of chest deformation. The methodology presented here produced novel kinematic data that will be useful in developing biofidelic human models.

The absence of data on the load deflection and energy absorption characteristics of vehicle interiors has been a factor which limits the accuracy of crash victim simulations. A recent test program conducted for the National Highway Traffic Safety Administration has developed data on the interactions of dashboards and knee panels with chests and knees. This paper summarizes the test results for several vehicles and shows how these results are used in simulating vehicle crash tests. Comparisons between crash tests and computer reconstruction using the 3-Dimensional Crash Victim Simulator (CVS-3D) for a late model car are included. The simulation shows good agreement with test and illustrates the application of available static and dynamic test data to improve occupant simulations.

This paper presents an overview of work performed by the National Highway Traffic Safety Administration's (NHTSA) Vehicle Research and Test Center (VRTC) to test, validate, and improve the planned National Advanced Driving Simulator's (NADS) vehicle dynamics simulation. This vehicle dynamics simulation, called NADSdyna, was developed by the University of Iowa's Center for Computer-Aided Design (CCAD) NADSdyna is based upon CCAD's general purpose, real-time, multi-body dynamics software, referred to as the Real-Time Recursive Dynamics (RTRD), supplemented by vehicle dynamics specific submodules VRTC has “beta tested” NADSdyna, making certain that the software both works as computer code and that it correctly models vehicle dynamics. This paper gives an overview of VRTC's beta test work with NADSdyna. The paper explains the methodology used by VRTC to validate NADSdyna.

NHTSA uses a variety of computer modelling techniques to develop and evaluate test methods and mitigation concepts, and to estimate safety benefits for many of NHTSA's research activities. Computer modeling has been particularly beneficial for estimating safety benefits where often very little data are available. Also modeling allows researchers to augment test data by simulating crashes over a wider range of conditions than would otherwise be feasible. These capabilities are used for a wide range of projects from school bus to frontal, side, and rollover research programs. This paper provides an overview of these activities. NHTSA's most extensive modeling research involves developing finite element and articulated mass models to evaluate a range of vehicles and crash environments. These models are being used to develop a fleet wide systems model for evaluating compatibility issues.

This paper presents an overview of NHTSA's vehicle aggressivity and fleet compatibility research activities. This research program is being conducted in close cooperation with the International Harmonized Research Agenda (IHRA) compatibility research group. NHTSA is monitoring the changing vehicle mix in the U.S. fleet, analyzing crash statistics, and evaluating any implications that these changes may have for U.S. occupant safety. NHTSA is also continuing full-scale crash testing to develop a better understanding of vehicle compatibility and to investigate test methods to assess vehicle compatibility.

The paper discusses the development of a model for the 2006 BMW 330i for the National Advanced Driving Simulator's (NADS) vehicle dynamics simulation, NADSdyna. The front and rear suspensions are independent strut and link type suspensions modeled using recursive rigid-body dynamics formulations. The suspension springs and shock absorbers are modeled as force elements. The paper includes parameters for front and rear semi-empirical tire models used with NADSdyna. Longitudinal and lateral tire force plots are also included. The NADSdyna model provides state-of-the-art high-fidelity handling dynamics for real-time hardware-in-the-loop simulation. The realism of a particular model depends heavily on how the parameters are obtained from the actual physical system. Complex models do not guarantee high fidelity if the parameters used were not properly measured. Methodologies for determining the parameters are detailed in this paper.

The paper discusses the development of a model for a 1998 Chevrolet Malibu for the National Advanced Driving Simulator’s (NADS) vehicle dynamics simulation, NADSdyna. The Malibu is the third vehicle modeled for the NADS, and this is the third paper dealing with model development. SAE Paper 970564 contains details of the model for the 1994 Ford Taurus and SAE Paper 1999–01-0121 contains details of the model for the 1997 Jeep Cherokee. The front and rear suspensions are independent strut and link type suspensions modeled using recursive rigid body dynamics formulations. The suspension springs and shock absorbers are modeled as elements in the rigid body formulation. To complement the vehicle dynamics for the NADS application, subsystem models that include tire forces, braking, powertrain, aerodynamics, and steering are added to the rigid body dynamics model. The models provide state-of-the-art high fidelity vehicle handling dynamics for real-time simulation.