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Based on a long recognized need, the National Highway Traffic Safety Administration (NHTSA) has begun to reexamine the potential for international harmonization of side impact requirements. To this end, NHTSA, as directed by the U.S. Congress, has recently submitted a report to the Congress on the agency plans for achieving harmonization of the U.S. and European side impact regulations. The first phase of this plan involves crash testing vehicles compliant to FMVSS 214 to the European Union side impact directive 96/27/EC. This paper presents the results to date of this research. The level of safety performance of the vehicles based on the injury measures of the European and U.S. side impact regulations is assessed.

Diffuse brain injuries are very common in side impacts, accounting for more than half of the injuries to the head. These injuries are often sustained in less severe side impacts. An English investigation has shown that diffuse brain injuries often originate from interior contacts, most frequently with the side window. They are believed to be mainly caused by quick head rotational motions. This paper describes a test method using a Hybrid III dummy head in a wire pendulum. The head impacts a simulated side window or an inflatable device, called the Inflatable Curtain (IC), in front of the window, at different speeds, and at different impact angles. The inflated IC has a thickness of around 70 mm and an internal (over) pressure of 1.5 bar. The head was instrumented with a three axis accelerometer as well as an angular velocity sensor measuring about the vertical (z) axis. The angular acceleration was calculated.

This paper provides an overview of a cooperative research program between General Motors Corporation and the National Highway Traffic Safety Administration to conduct a field operational test of a rear-end collision warning system. A description of the system architecture is also presented.

Pedestrian research and testing at the NHTSA Vehicle Research and Test Center has recently focused on assessment of proposed ISO and EEVC head impact test procedures, and extension of these procedures to additional vehicle frontal surfaces. In addition to test parameter sensitivity evaluation, reconstruction of PCDS (Pedestrian Crash Data Study) cases with laboratory impact tests and computer simulations has been conducted. This paper presents the results of this research.

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.

In August of 2000, the National Highway Traffic Safety Administration (NHTSA) completed an Automated Collision Notification (ACN) Field Operational Test (FOT) in Erie County, New York, that combined crash sensing, position location, and wireless communications technology in a system with the goal of saving lives and reducing disabilities from injuries by providing faster and more informed emergency medical responses to serious injury crashes. The ACN FOT Team designed and built an ACN system prior to the start of the test period in July 1997. ACN in-vehicle systems were than installed in 850 vehicles. The crash notification messages were delivered to emergency response and dispatch equipment installed at the Erie County Sheriff's Office, which served as the Public Safety Answering Point (PSAP) for this FOT.

Several thoracic and head protection side impact air bag systems (SAB) are emerging in the U.S. market and are projected to become prevalent in the fleet. These systems appear to offer superior protection in side crashes. However, concerns have been raised as to their potential for causing injury to out-of-position (OOP) occupants. This paper describes the National Highway Traffic Safety Administration (NHTSA) program for evaluation of the SAB systems for OOP occupants and provides a status report on the current research. The industry's Side Airbag Out-of- Position Injury Technical Working Group (TWG) recommended procedures for 3-year-old and 6-year-old occupants are evaluated. Additional test procedures are described to augment the TWG procedures for these occupants and 12-month- old infants.

Phase IV of the National Highway Traffic Safety Administration's (NHTSA) rollover research program was performed during the spring through fall of 2001. The objective of this phase was to obtain the data needed to select a limited set of maneuvers capable of assessing light vehicle rollover resistance. Five Characterization maneuvers and eight Rollover Resistance maneuvers were evaluated [1]. This paper is “Volume 2” of a two-paper account of the research used to develop dynamic maneuver tests for rollover resistance ratings. Test procedures and results from four Rollover Resistance maneuvers are presented. The Consumers Union Short Course (CUSC), ISO 3888 Part 2, Ford Path Corrected Limit Lane Change (PCL LC), and Open-Loop Pseudo Double Lane Changes are discussed. Details regarding the NHTSA J-Turn, and the three fishhook maneuvers are available in “Volume 1” [2].

Phase IV of the National Highway Traffic Safety Administration's (NHTSA) rollover research program was performed in 2001, starting in the spring and continuing through the fall. The objective of this phase was to obtain the data needed to select a limited set of maneuvers capable of assessing light vehicle rollover resistance. Five Characterization maneuvers and eight Rollover Resistance maneuvers were evaluated [1]. This paper is “Volume 1” of a two-paper account of the research used to develop dynamic maneuver tests for rollover resistance ratings. Test procedures and results from one Characterization maneuver (the Slowly Increasing Steer maneuver) and four Rollover Resistance maneuvers are discussed (the NHTSA J-Turn, Fishhook 1a, Fishhook 1b, and Nissan Fishhook). Details regarding NHTSA's assessment of the Consumers Union Short Course (CUSC), ISO 3888 Part 2, Ford Path Corrected Limit Lane Change (PCL LC), and Open-Loop Pseudo Double Lane Changes are available in “Volume 2” [2].

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.

This paper attempts to define and measure factors related to a vehicle's performance that are influential in the causation of rollover accidents. Data are presented which define the rollover involvement rates for many non-vehicular factors. A brief description of the vehicle metrics and the analysis procedures used in the rollover prevention rulemaking program are included along with a set of conclusions. The program evaluated many vehicle metrics related to vehicle rollover, analyzed accidents from 5 states, and compared the two data bases by testing “cause and effect” hypotheses by performing statistical regressions to determine levels of correlation. Location of the crash, urban vs. rural, was a strong predictor of the crash outcome - that is, rollover or non-rollover. Vehicle class and single vehicle accident rate were also statistically significant, as well as, whether or not the vehicle was equipped with anti-lock brakes. Several other driver demographics were significant.

When a heavy vehicle driver (or in fact a driver of any vehicle) makes a brake application that is too "hard" for conditions - especially when the vehicle is lightly loaded or empty and/or the road is wet or slippery - he is likely to lock some or all of his wheels. Under these conditions, the tractor can jackknife or the trailer can swing out of its lane (if it is a combination-unit vehicle) or the truck can spin out (if it is a single-unit vehicle). Incorporation of an antilock brake system addresses the wheel lock and resultant control loss.

This paper presents recent results of on-going research to build new maps of driver performance in car-following situations. The novel performance map is comprised of four driving states: low risk, conflict, near crash, and crash imminent - which correspond to advisory warning, crash imminent warning, and crash mitigation countermeasures. The paper addresses two questions dealing with the approach to quantify the boundaries between the driving states: (1) Do the quantified boundaries strongly depend on the dynamic scenario encountered in the driving environment? and (2) Do the quantified boundaries vary between steering and braking driver responses? Specifically, braking and steering driver performances are examined in two car-following scenarios: lead vehicle stopped and lead vehicle moving at lower constant speed.

This paper describes the results of a study conducted to evaluate the performance and accuracy of a medium size sedan finite element model for off-set car-to-car impacts. This model was originally developed for front impact and does not include side structure compliance. Two tests conducted by the National Highway Traffic Safety Administration are used for evaluation of the simulations. The overall results indicate that the simulations appear to be consistent with the crash test data. Problems associated with the use of node constraints, lack of side structure model fidelity, and the different integration time marching are identified and solutions for the problems are proposed.

The National Highway Traffic Safety Administration has initiated research to develop performance specifications for dummy-based accelerometers in the crash test environment, and to provide criteria for defining and establishing equivalent performance among accelerometers from different manufacturers. These research efforts are within the general guidelines on transducer equivalency outlined in the current revision of the Society of Automotive Engineers recommended practice, Instrumentation for Impact Test, SAE 211/2 March 1995. Representative data from vehicle crash and component level tests have been analyzed to determine the acceleration levels and frequency content in a realistic dynamic environment for dummy-based accelerometers.

An important new technique in safety engineering for complex systems is the fault tree analysis method. The results of a motor vehicle brake system safety analysis using the fault tree technique are described. The work is directed toward the identification and ranking of brake system failure modes which may be critical as accident causation factors. Safety criticality for each failure mode is defined as the product of probability of occurrence and severity of effect on vehicle control. Failure data for the brake system components are obtained from maintenance and repair records of a large automobile leasing fleet. An effect scale is developed using a method for pooling expert judgements to obtain the relative ranking of various brake faults as to accident causation potential. The fault tree structure is employed to combine probability and effect to obtain the safety criticality value of each fault.

This paper addresses serious, occupant crash injuries from: (a) head impacts with A-pillars, roof headers, and roof side rails, and (b) occupant entrapment and roof intrusion in rollover accidents. It also discusses two less frequent causes of injury: (a) fires in crashes, and (b) occupant ejection through the roof and rear window or rear doors. The paper estimates the relative frequencies of these types of injuries, classified according to the body area injured and the vehicle interior component responsible for the injury. Data for these estimates is from the National Crash Severity Study augmented by the 1979 Fatal Accident Reporting System data. Also, this paper addresses the potential for reducing the severity of these injuries in light motor vehicles, with particular emphasis on AIS 3 and more serious injuries.

The frontal crash standard in the USA specifies that the full front of a vehicle impact a rigid barrier. Subsequently, the European Union developed a frontal crash standard that requires 40 percent of the front of a vehicle to impact a deformable barrier. The present study conducted paired crashes of vehicles using the full-frontal barrier procedure and the 40 percent offset deformable barrier procedure. In part, the study was to examine the feasibility of adding an offset test procedure to the frontal crash standard in the USA. Frontal-offset and full-frontal testing was conducted using both the mid-size (50th percentile male Hybrid III) and the small stature (5th percentile female Hybrid III) dummies. Five vehicle models were used in the testing: Dodge Neon, Toyota Camry, Ford Taurus, Chevrolet Venture and Ford Contour. In the crash tests, all dummies were restrained with the available safety belt systems and frontal air bags.

This paper describes a Field Operational Test (FOT) of an Automated Collision Notification (ACN) System, a new way to provide definitive pre- hospital medical care to people injured in motor vehicle crashes. This FOT is part of the National Highway Traffic Safety Administration's (NHTSA's) research being conducted under the U.S. Department of Transportation's Intelligent Transportation Systems (ITS) program. Management of the program is by the Office of Vehicle Safety Research in NHTSA. The ACN FOT is a demonstration of the application of advanced technology for the improvement of pre-hospital emergency care for motor-vehicle crash victims. The test, involving approximately 850 volunteers' vehicles, was conducted in rural Western New York State. A partnership of local public agencies and private corporations, led by Veridian, Inc., performed the test.