Search Results

This investigation addresses and evaluates: (1) belted drivers in frontal crashes; (2) crashes divided into low, medium, and high severity; (3) air-bag-equipped passenger vehicles separated into either model years 1985 - 1997 (with airbags) or model years 1998 - 2008; (4) rate of Harm as a function of crash severity and vehicle model year; and (5) injury patterns associated with injured body regions and the involved physical components, by vehicle model year. Comparisons are made between the injury patterns related to drivers seated in vehicles manufactured before 1998 and those manufactured 1998 or later. The purpose of this comparative analysis is to establish how driver injury patterns may have changed as a result of the introduction of more recent safety belt technology, advanced airbags, or structural changes.

This study assessed the primary involved physical components attributed to the head and face injuries of child occupants seated directly adjacent to the stuck side of a vehicle in a side impact collision. The findings presented in this study were based upon analysis of the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS) for the years 1993–2007. Injury analysis was conducted for those nearside child occupants aged between 1–12 years-old. The involved children were classified as toddler-type, booster-type, or belted-type occupants. These classifications were based upon the recommended restraint system for the occupant. Injury mechanisms were assessed for the child occupants in each of the three groups. A detailed study of NASS/CDS cases was conducted to provide a greater understanding of the associated injury mechanisms.

Real world crashes in NASS/CDS 1997 to 2000 were examined individually in order to find patterns in single vehicle rollover crashes. Typical maneuver induced rollovers of SUV's were reconstructed using the HVE model. From HVE and roll event reconstructions, the values of longitudinal, lateral, and vertical displacement, and roll, pitch, and yaw angle, for the pre-roll and rollover event were calculated. These values were used as inputs to a MADYMO model for simulated vehicle motion to predict occupant kinematics. Both near-side and far-side rollovers were simulated. The MADYMO model provided estimates of head velocity for the various rollover scenarios for a belted driver. In both near-side and far-side rollovers of the type reconstructed, the lateral component of head velocity was the greatest. Maximum head velocities of 5.3 m/s were predicted. The simulations were for two complete rollovers. The highest head velocity occurred during the first three quarter turns.

This paper presents an analysis of the National Automotive Sampling System (NASS) and the Fatal Accident Reporting Systems (FARS) data for the combined years 1988–97 with respect to side impacts. Accident variables, vehicle variables, occupant variables and their interactions have been considered, with special emphasis on occupant injury patterns. The crash modes considered are car-to-car, car-to-LTV (light trucks and vans) and car to narrow object, with special emphasis on the latter two. This study was undertaken to obtain a better understanding of injury patterns in lateral impacts, their associated causation factors, and to obtain information that will assist in prioritizing crash injury research problems in near side impacts. Of particular interest is the increase in the population of light trucks and vans and their influence on side impact priorities. Conclusions will be drawn regarding the frequency and injury severity of car-to-LTV’s and car to narrow objects.

Comfort and safety are major considerations in the design of occupant seats in motor vehicles. In rear impacts, the seat is the principal component of the occupant restraint system. However, it also contributes to occupant restraint in frontal. and side impacts, and rollovers. To determine how well automobile seats protect occupants from injuries in rear impacts, crash data from the national accident files in the united states were analyzed. The distributions and causes of injuries in rear impacts were categorized according to injured body region and source of injury. In addition, forty-nine selected accident cases were reviewed, to determined how the seat performed in crashes. Finally, rear impact crash tests of passenger cars were analyzed to determine dummy motion and seat performance. Non-contact injuries were associated with the largest portion of injury harm. The seat and frontal components were the two largest sources of contact injury harm.

This investigation addresses and evaluates the injury patterns of car occupants, as a function of air bag deployment with or without belt use. A companion paper provides a comprehensive evaluation of air bag field performance, in comparison with the no restraint,or other restraint conditions,concerning: Cars, Exposure, Occupants, Restraints, & Protection provided by the restraints. The findings reported in this investigation are based exclusively on the data contained in the records of NHTSA's NASS/CDS1988-1992. The investigation focuses on car drivers. Because of the relatively late and limited introduction of air bags, all other light vehicle populations are either not represented, or represented by a very meager sample in the sources cited above.

This investigation encompasses a comprehensive evaluation of air bag field performance, in comparison with the no restraint, or other restraint conditions. The paper at hand addresses: Cars, Exposure, Occupants, Restraints, & Protection provided by the restraints. A companion paper addresses the injury patterns of car occupants. The findings of the investigation are based on two primary sources of national coverage: (i) the field crash experience contained in the records of NHTSA's NASS/CDS 1988-1992; and (ii) the fatal accident experience contained in NHTSA's FARS 1991-1993. The investigation focuses on car drivers. Because of the relatively late and limited introduction of air bags, all other light vehicle populations are either not represented, or represented by a very meager sample in the sources cited above.

This paper is based on the crash and casualty experience compiled by the National Highway Traffic Safety Administration's (NHTSA) National Accident Sampling System, Crashworthiness Data (NASS/CDS 1988-1992), and by the William Lehman Injury Research Center (University of Miami/Jackson Memorial Hospital/Ryder Trauma Center) crash data files. The NASS/CDS files provide data on injuries to occupants in all types of tow-away crashes. The William Lehman Injury Research Center files provide detailed crash analysis and injury documentation of more than 100 restrained occupants with injuries from frontal crashes. These files provide a basis for recognizing injury patterns among restrained occupants and postulating their causes. The purpose of this paper is to report on an observed pattern of liver and spleen injuries suffered by drivers wearing shoulder belts without the lap belt fastened.

The William Lehman Injury Research Center has conducted multi-disciplinary investigations of fifty crashes involving drivers protected by air bags. In all cases, serious injuries were suspected. Nine cases involved fatal injuries. These cases are not representative of crashes in general. However, when used in conjunction with NASS/CDS they provide insight into the most severe injuries in crashes of vehicles equipped with air bags. A comparison with data from the National Accident Sampling System; Crashworthiness Data System (NASS/CDS) shows that head injury and abdominal injury make up a larger fraction in the Lehman data than in NASS/CDS. Examination of fatal cases indicates that head injuries are frequently caused by intruding structure or by unfavorable occupant kinematics among the unrestrained population.

The William Lehman Injury Research Center has conducted multi-disciplinary investigations of one hundred seventy-eight crashes involving adult occupants protected by safety belts and air bags. In all cases, serious injuries were suspected. Nine cases involved serious heart injuries. These cases are not representative of crashes in general. However, when used in conjunction with National Accident Sampling System; Crashworthiness Data System (NASS/CDS) they provide insight into the most severe injuries suffered by restrained occupants in frontal crashes. Heart injuries are rare, but when they occur they are usually life threatening. NASS/CDS shows that heart injuries comprise about 0.2% of the injuries in frontal tow-away crashes. In the NHTSA file of Special Crash Investigations (SCI) of air bag cases, heart injuries are reported in 1% of the occupants over 15 years of age. Twenty-five percent of the fatally injured occupants had heart injuries, and 83% of those with heart injury died.

This work addresses and evaluates the likelihood of human casualty in highway crashes, projected on the basis of field crash data that may become available electronically by sensors at crash time, and/or observed at the crash scene by emergency attendants. Termed collectively as a “crash signature”, such data are treated as predictors and are selected from: crash severity, general area of damage, direction of force, occurrence of rollover, intrusion, vehicle crush and its specific horizontal location, collision partner, vehicle class and size, occupant age, gender, restraint use and type, seating position, and other. Crash signatures are converted into responses such as: (a) the likelihood of the most severe outcome, fatality or survived injury, by severity AIS per occupant; and (b) the same per vehicle. Cars are the vehicles selected for this investigation.

Automobile insurance claims of two popular midsize cars with different air bag deployment frequencies -- the Dodge/Plymouth Neon and Honda Civic -- were examined to determine performance in higher severity crashes (the upper 30 percent of crashes ranked by adjusted repair cost). Previously, it was found that drivers sustained more, mainly minor, injuries in the Neon which had a higher deployment frequency in low speed crashes. This study examined, for these two cars, whether there was any trade-off associated with a higher deployment threshold. It was found that even at higher speeds, the Neon had a greater frequency of air bag deployments, which in turn resulted in a greater likelihood of driver injury. Once again upper extremity injuries were most prevalent for Neon drivers and were highest for female drivers. At the same time, there was little evidence that driver protection was compromised in the Civic in the more important high speed crashes.

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 paper presents the methodology and results of an analysis of the available information on motor vehicle accident occurrence which could be used to provide a basis for establishing priorities for future Government and private sector work directed at enhanced crash avoidance or mitigation. The work was stimulated by several factors: (1) the absence of a recent and updated framework for problem evaluation; (2) motor vehicles have changed substantially in the past several years; (3) the quantity and quality of accident data and vehicle accident avoidance performance information have increased very substantially over the past 5 years; and (4) Government policies and the amount of Government and private sector resources available for future work have changed. This study takes the Agency's automated files on accident experience as the baseline information on motor vehicle involvement in accidents of all types.

The Crash Victim Simulator Three Dimensional Model (CVS-3D) allows the simulation of the kinematics and responses of a motor vehicle occupant or pedestrian during a crash. This paper summarizes the data requirements for the CVS-3D Model, the sources of data, and the research underway to provide additional data for modeling the occupant and the vehicle. An example of the use of the model in reconstructing an offset frontal accident is included. The results computed by the model are quite reasonable when compared with the injuries received by the occupant. The insights into the events which occurred during the crash are excellent.

The subject is treated on the basis of detailed engineering test data regarding components and parameters of 1975 autos. The applicability of the simulation approach is examined by extensive comparisons with integrated vehicle test results. It is found that fuel economy, for the EPA driving schedules, is adequately simulated with 5% to 10% uncertainties. Uncertainties of the same magnitude are also encountered in performance simulations. Larger uncertainties are evident in the simulation of emissions. NOx prediction has an uncertainty up to 25% but no significant bias, while CO and HC are very substantially over-predicted and under-predicted respectively. Excepting HC and CO, several applications are made in the evaluation of sensitivities to various auto components and parameters. Evaluations are made of changes in auto weight, engine displacement and rear axle ratio, considered individually and in combinations.

The subject is treated by statistical and engineering analyses applied to extensive measurements of fuel economy and acceleration performance. Fuel economy data are provided by the EPA certification lists for the four years 1973 to 1976. The performance data are track measurements of 0 to 60 MPH acceleration times for 1974 and 1975 vehicles, as reported in the popular automotive literature. Several relations, supported by engineering analyses, are selected for making least-squares fits to the extensive measurements. The pivotal variables include: inertia weight, horsepower, engine displacement and rear axle ratio, individually and in combinations. Satisfactory fits are made by power factorial forms and the resulting algorithms have standard errors of estimate in the vicinity of 10% for fuel economy and in the range 10% to 15% for acceleration time.

This paper addresses the crash protection of occupants of the car fleet in transition from the late 1970's to the early 1980's. Three files of the National Highway Traffic Safety Administration are used: the NASS 1979 to 1983, the PARS 1979 to 1983, and the NCSS 1977 to 1979. Fatalities, injured survivors by severity, and all accident involved car occupants are addressed. Risks of crash and injury outcomes are determined and analyzed as a function of risk influencing factors, especially factors that may vary significantly during the time period under consideration. Ejection risks and ejection patterns are addressed explicitly. Harm, an earlier introduced human casualty integrator, and harm distributions are extensively examined and updated with respect to earlier results. Harm and harm pattern changes, whether statistical fluctuations or systematic variations, are analyzed.

This paper addresses the risks of occupant casualties in highway accidents. Such risks are determined from U.S. accident experience in the past 10 years. Risks are analyzed as a function of vehicle type, car market class, make, nameplate, and model year for crashes of various impact types and various severities. Both absolute risks, per unit exposure, and relative risks are addressed. The influence of many exposure variables is examined and necessary adjustments, to a common set of exposure conditions, are made. The control variables for this purpose are: calendar year and car age; occupant's seating position, restraint status, and age; time and place of travel; and various roadway characteristics. Adjusted risks are reviewed versus major characteristics of cars as implied by make, nameplate, and model year. Occupant ejections and rollovers receive special attention due to their risk sensitivity to car class

The CVS/ATB (Crash Victim Simulator/ Articulated Total Body) computer program solves the equations of motion in three dimensional space for a set of rigid bodies connected by joints. The program permits the specification of contact interaction properties between the rigid bodies and the surrounding environment. It is, therefore, possible to specify initial conditions of motion for the rigid bodies, and calculate the subsequent motion resulting from the forces imposed by the environment. The program is sufficiently general that it can be applied to a wide range of physical dynamic situations. However, the principal motivation for its development was to evaluate the interactions of the human body with the environment inside a motor vehicle during a crash. Subsequently, it has been applied to a number of other dynamic simulations including pedestrian to vehicle impacts and the emergency escape of air crew from aircraft. The CVS/ATB program is in the public domain.