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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.

Given the increased use of programmable embedded electronic systems (PEES) in automotive applications and their vital importance, it is not only important for engineers to design PEES in such a way to meet or exceed safety requirements but also quantify how “safe” these systems are. At the University of Virginia's Center for Safety-Critical Systems, we have developed a safety quantification methodology for embedded real time safety-related systems. The goal of the safety quantification methodology is to provide a generic but rigorous and systematic way of characterizing the dependability behavior of embedded systems that is applicable to a broad range of applications from automotive to nuclear. This paper presents a quantitative safety assessment methodology for safety-critical embedded systems using fault injection (FI). This methodology has been developed, refined and applied to a number of commercial safety-grade systems in the railway, nuclear and avionics industries.

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.

A low cost system has been developed to measure a vehicle's lateral position relative to the lane markings on a roadway. The system is capable of tracking white or orange lines, solid or dashed edge lines, while operating in daylight or at night. The tracking system is comprised of two “off-the-shelf” black and white charge coupled device (CCD) video cameras along with commonly available electronic components. The lane tracking system is capable of outputting real time data at 30Hz through an analog output. Using the data from this sensor system it is possible to detect lane changes, determine the magnitude and duration of lane exceedances, and other metrics commonly used by researchers in the transportation community. This paper will discuss the design and performance of the system, processing of the raw lane tracker data, and the benefits and limitations of the technology.

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 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.

This paper discusses the consumer and news media perceptions about air bags that had to be taken into account by the National Highway Traffic Safety Administration in making rulemaking decisions in 1997. Addressing these perceptions was a major concern as the agency made preparations to allow identifiable groups of people at risk from an air bag deployments to have on-off switches installed in their vehicles.

The rapid development of driver assistance systems, such as lane-departure warning (LDW) and lane-keeping support (LKS), along with widely publicized reports of automated vehicle testing, have created the expectation for an increasing amount of vehicle automation in the near future. As these systems are being phased in, the coexistence of automated vehicles and human-driven vehicles on roadways will be inevitable and necessary. In order to develop automated vehicles that integrate well with those that are operated in traditional ways, an appropriate understanding of human driver behavior in normal traffic situations would be beneficial. Unlike many research studies that have focused on collision-avoidance maneuvering, this paper analyzes the behavior of human drivers in response to cut-in vehicles moving at similar speeds. Both automated and human-driven vehicles are likely to encounter this scenario in daily highway driving.

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.

The application of optical diagnostics in turbulent reactive flows often suffers from the beam steering (BS) effects, resulting in degraded image quality and/or measurement accuracy. This work investigated a method to correct the BS effects to improve the accuracy of optical diagnostics, with particle imagine velocimetry (PIV) measurements on turbulent reactive flames as an example. The proposed method used a guiding laser to correct BS. Demonstration in laboratory turbulent flames showed promising results where the accuracy of PIV measurement was significantly enhanced. Applicability to more complicated and practical situations are discussed.

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.

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.

Current state-of-the-art vehicles implement pedestrian protection features that rely on pedestrian detection sensors and algorithms to trigger when impacting a pedestrian. During the development phase, the vehicle must “learn” to discriminate pedestrians from the rest of potential impacting objects. Part of the training data used in this process is often obtained in physical tests utilizing legform impactors whose external biofidelity is still to be evaluated. This study uses THUMS as a reference to assess the external biofidelity of the most commonly used impactors (Flex-PLI, PDI-1 and PDI-2). This biofidelity assessment was performed by finite element simulation measuring the bumper beam forces exerted by each surrogate on a sedan and a SUV. The bumper beam was divided in 50 mm sections to capture the force distribution in both vehicles. This study, unlike most of the pedestrian-related literature, examines different impact locations and velocities.

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.

Strategies for the inoculation of bioreactors for long-term space missions include communities of diverse composition or, alternatively, communities of a few organisms selected for their ability to efficiently catalyze reactions of interest in the reactor. The concept of functional redundancy states that in a diverse community, several different organisms may be present that are capable of effecting processes necessary to the maintenance of the system function. The concept implies that if some members of the community are lost, others will be able to keep the system from failing in the critical reactions that take place therein. In a sewage reactor in the laboratory, a diverse community at steady state was perturbed by elimination of aeration for seven days. Chemical pools (NH4+, NO3-, dissolved O2), pH, and CO2 evolution were monitored before, during, and after the perturbation.

This paper focuses on two types of electronics-based object detection systems for heavy truck applications: those sensing the presence of objects to the rear of the vehicle, and those sensing the presence of objects on the right side of the vehicle. The rearward sensing systems are intended to aid drivers when backing their vehicles, typically at very low “crawl” speeds. Six rear object detection systems that were commercially available at the time that this study was initiated were evaluated. The right side looking systems are intended primarily as supplements to side view mirror systems and as an aid for detecting the presence of adjacent vehicles when making lane changes or merging maneuvers. Four side systems, two commercially available systems and two prototypes, were evaluated.

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.