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About 8,000 pedestrians are killed each year in the United States and probably another 180,000 are injured. This paper reports on an analysis of 1978 and 1979 New York pedestrian accidents to try to find any relationships between vehicle factors and pedestrian injury severity and location. In these data trucks and vans were found to be associated with more severe pedestrian injuries than passenger cars. However, within the passenger car category vehicle weight and injury severity were not clearly related. And few meaningful relationships were found between aspects of the passenger car front end configuration or the past production use of "soft" materials and pedestrian injury severity or location.

The effectiveness of restraint systems in preventing fatalities or reducing injury has been estimated by extrapolation of data from several sources: (1) Sled tests with dummies (2) Analysis of accident case studies (3) Statistical comparison of belted and unbelted persons in crashed cars. (4) Before and after studies (e.g., with respect to belt-usage legislation, or as with the 1974 starter-interlock program) Fatality reduction estimated by the case study method is on the order of 30 percent, but by the statistical comparison method at 50 percent or sometimes as high as 60 percent. Other differences (e.g., driving habits) between belted and unbelted persons explain the disagreement between the two estimates. More complete analysis of available accident data suggests that the higher values were obtained without correction for such factors as crash severity or occupant age.

This study Investigates the response of human cadavers1, and live anesthetized and post-mortem primates and canines2, to blunt lateral thoraco-abdominal impact. There were 12 primates: 5 post-mortem and 7 live anesthetized; 10 canines; 1 post-mortem and 9 live anesthetized; and 3 human cadavers. A 10 kg free-flying mass was used to administer the impact in the right to left direction. To produce the varying degrees of injury, factors including velocity, padding of the impactor surface, location of impact site, and impactor excursion were adjusted. The injuries were evaluated by gross autopsy, and in the case of live subjects, current clinical methods such as sequential peritoneal lavage and biochemical assays were also employed. Mechanical measurements included force time history, intraortic pressure, and high-speed cineradiography to define gross organ motion.

A sample population of 51 male and 57 female subjects ranging in age from 18 to 78 years was assembled and tested in six different vehicles for preferred seat positions under non-driving and driving conditions. Volunteer subjects were selected by age, stature, and weight criteria in order to match the U.S. adult population to the extent practical. Preliminary analyses of these data suggest that on a total sample basis there is little difference between seat positions selected under non-driving and driving conditions, but that individuals may show significant differences. The small differences in group mean positions observed in this study may be due to a seat belt and/or an initial seat position factor. Post-drive seat position results were analyzed in a variety of ways to identify factors that may influence a person's preferred seat position.

This paper presents the various features and operational properties of a two-dimensional mathematical model of crash victim motions. The earliest forms of this model can be traced to the early 1960s. Developmental work on two-dimensional models then continued both within the automotive industry and in independent organizations such as the Highway Safety Research Institute (HSRI). The most recent product of this activity is the MVMA two-dimensional mathematical crash victim simulation developed at HSRI for the Motor Vehicle Manufacturers Association. The features of this model include: 1. An eight mass representation of the human body where contact between the crash victim and the vehicle is represented in terms of independent force-deformation properties of the victim and the vehicle. 2. An extensible multi-joint neck and a realistically flexible shoulder joint. 3. A real-line representation of the vehicle interior or exterior where shape is given as a network of points. 4.

The current federal accident data collection system is inadequate. It does not produce representative data essential for answering cause-and-effect questions concerning accidents, injuries, and fatalities, and it does not produce adequate data essential for conducting cost-benefit analyses of changes in vehicle designs, highway designs, or driver licensing policies. A proposed federal data collection system (SIR) can solve those problems at a total cost of about $6 million a year. The SIR system would include 30 investigating teams precisely located throughout the U.S., and would include a Sampling program, an In-depth program, and a Rapid-response program. The sooner this system is established, the sooner government and industry will begin to obtain accurate and reliable answers to pressing questions in the field of highway safety.

Advanced crash-impact protective equipment and techniques which have application to crew and passenger crash safety in jet transport aircraft have been evaluated. Thirty-two state-of-the-art concepts have been analyzed from a systems engineering viewpoint with respect to several engineering, psychological, and medical disciplines. In order to provide a framework to determine the function level of each concept, an event-oriented flow chart of the crash and escape event has been prepared. The 17 events occurring during a crash are included, beginning with system installation and concluding with emergency evacuation of a disabled aircraft. Performance with respect to the events on the flow chart are rated in terms of hazards of system use, maintainability, reliability, human factors, and other technological considerations.

Serious injuries are caused to the chest and thoracic organs both in front and side automobile collisions, and statistical surveys indicate that overall chest injuries are the third most frequent after head and the lower limbs. For safer design of restraint systems and vehicle interiors experimental data has to be obtained to establish chest injury criteria. Unembalmed human cadavers were used to conduct nine frontal and fourteen lateral impacts including four with a simulated arm rest. All impacts used a six inch (15.2 cm) diameter impactor with impact velocities ranging from 12 mph (19.3 kph) to 20 mph (32.2 kph). Chest impacts were also conducted on rhesus monkeys and baboons to establish primate-human injury scaling criteria. Four human volunteers were used to obtain static load deflection curves in the lateral and frontal directions. The results of the above experiments and those conducted by other investigators are presented and analyzed.

Blunt abdominal trauma is a major cause of death in the United States. However, little experimental work has been done to clarify the mechanism of blunt abdominal injury and to quantify tolerance parameters for the abdominal organs. This paper describes a joint study by the Highway Safety Research Institute and the Section of General Surgery of The University of Michigan in which direct impacts were applied to livers and kidneys. The tests were performed in a high-speed testing machine at a controlled ram velocity and stroke limit. The organ was surgically mobilized in anesthesized Rhesus monkeys and then placed on a load cell while still being perfused in the living animal. Tests were performed at ram speeds of 120, 6000, and 12000 in/min (5, 250,and 500 cm/s). The resulting load-deflection data were normalized and average stress-strain curves plotted for each test. In addition, the resulting injury severity was estimated immediately after impact using an injury scale of 1 to 5.

The object of this research program has been to extend the scope of earlier work to include long-duration head impacts and to develop new scaling relationships to allow extrapolation of impact data from infrahuman primates to living humans. A series of living primate side impacts to the head and torso was conducted in parallel with a series of impacts to human cadavers. Dimensional analysis techniques were employed to estimate in vivo human tolerance to side injury. The threshold of closed brain injury to humans was found to be 76 g for a pulse duration of 20 ms and an impact velocity of 43 ft/s (13.2 m/s). The maximum tolerable penetration to the chest was found to be 2.65 in (6.72 cm) for both the left and right sides. Scaling of abdominal injuries to humans was accomplished by employing a factor that relates impact contact area, animal mass, impact force, and pulse duration to injury severity.

Basic physical characteristics of the neck have been defined which have application to the design of biomechanical models, anthropometric dummies, and occupant crash protection devices. The study was performed using a group of 180 volunteers chosen on the basis of sex, age (18-74 years), and stature. Measurements from each subject included anthropometry, cervical range-of-motion (observed with both x-rays and photographs), the dynamic response of the cervical flexor and extensor muscles to a controlled jerk, and the maximum voluntary strength of the cervical muscles. Data are presented in tabular and graphic form for total range-of-motion, cervical muscle reflex time, decelerations of the head, muscle activation time, and cervical muscle strength. The range-of-motion of females was found to average 1-12 deg greater than that of males, depending upon age, and a definite degradation in range-of-motion was observed with increasing age.

This paper describes the development of an improved neck simulation that can be adapted to current anthropometric dummies. The primary goal of the neck design is to provide a reasonable simulation of human motion during impact while maintaining a simple, rugged structure. A synthesis of the current literature on cervical spine mechanics was incorporated with the results of x-ray studies of cervical spine mobility in human volunteers and with the analysis of head-neck motions in human volunteer sled tests to provide a background for the design and evaluation of neck models. Development tests on neck simulations were carried out using a small impact sled. Tests on the final prototype simulation were also performed with a dummy on a large impact sled. Both accelerometers and high-speed movies were used for performance evaluation.

During recent years, the Highway Safety Research Institute (HSRI) has developed and validated two- and three-dimensional models describing the motions and forces acting upon an occupant during a collision. These inexpensive-to-operate models are performing with approximately 90% accuracy in parametric studies of classical crash configurations. In our own validation procedures, contacts with automobile development and design groups, and discussions with federal agencies, certain shortcomings of mathematical modeling procedures have been isolated. These include primarily the inability of the user to determine and input data to the computer programs and also to specify force, motion, velocity, and acceleration output data in a form applicable to the various vehicle design, human tolerance, and compliance tasks for which the models have been developed.

This paper discusses the development of adequate criteria and evaluation methods for seat belt restraint design. These criteria should include the effect of seat belts in abdominal injury as well as head injury. It is concluded that belt load limiters and energy-absorbing devices should limit head-to-vehicle contact, ensure that the lap belt maintains proper contact with the bony pelvic girdle, and limit the belt loads. Studies are made of pulse shape and belt fabrics. Currently available mathematical models are used for the studies included in the paper.

In a previous study, an extensive study of the dynamic performance of child seating systems indicated that little protection was provided under circumstances other than panic braking. This study was performed with impact test conditions of 30 mph frontal and 20 mph lateral and rear barrier impacts with seating systems meeting the requirements of FMVSS 213. Additionally, the performance of prototype seats developed under contract with the Department of Transportation under similar test conditions will be presented to compare the protective qualities available with seats of current design and those that could become available in the future. The performance of the child seats will be evaluated using two criteria, motion limits and acceleration limits. It is believed that the performance of child seats can be determined without the extensive test equipment and facilities required for adult seating and restraint systems.

This paper discusses the problem of occupant protection in severe rear-end collisions from the standpoint of high performance seat structures and head restraints. Consideration is given to both fixed head restraints and to deployable head restraints. Two-dimensional computer simulations of occupant kinematics in a variety of rear-end collisions are utilized to provide initial performance criteria for head restraint design configurations. The resulting prototype system underwent a test and development program on an impact sled. The results of the various prototype performances and general criteria for high performance head restraint systems are discussed.

Drivers carried out a lane-changing and passing maneuver using convex and plane exterior mirrors alone or in combination with a plane interior mirror. The data showed that the addition of the plane interior mirror compensated for judgmental errors found when convex mirrors were used alone. When the speed difference was 15 mph between the overtaking car and the subject's car, subjects accepted gaps that were too short irrespective of the exterior mirror type. The data suggested that exterior convex mirrors of radii greater than 30 in. may be used reasonably safely by drivers and would have the advantage of providing a considerably increased field-of-view compared to currently used exterior mirrors.

A study has been conducted as an initial step in determining the differences observed between the motions of a living human impact sled test subject and a dummy test subject. The mechanism which is proposed for accomplishing this is the HSRI Two-Dimensional Mathematical Crash Victim Simulator. A series of measurements were taken on human test subjects, including classical and nonclassical anthropometric measurements, range of motion measurements for the joints, and maximum foot force measurements. A series of mathematical expressions has been used to predict body segment weight, centers of gravity, and moments of inertia using the results of the various body measurements. It was then possible to prepare a data set for use with the mathematical model.

This paper describes an injury criteria model implemented in computer language, and a restraint system effectiveness index for evaluating the degree to which the vehicle environment can prevent or reduce occupant injuries. The need for criteria of this type is based on the fact that if the degree of protection offered to a vehicle occupant by a restraint system or a vehicle interior (a function of the distribution and magnitude of the forces transmitted to the occupant) could be expressed in quantitative terms, then, more meaningful comparisons could be made between restraint configurations, and, areas of needed biomechanical research and statistical accident investigations could be more readily identified on the basis of the sensitivity of the results when the injury or effectiveness criteria are applied. The injury criteria model consists of three parts: 1.

Present head restraint systems quite often restrict rearward visibility, and when not properly adjusted, their effectiveness suffers. The deployable head restraint can overcome both these problems and in addition provide head restraint performance better than fixed systems. This paper describes a project to study the feasibility of deployable head restraints. Starting with two-dimensional computer simulations of front seat occupant kinematics in rear-end collisions, initial performance criteria for deployment times, and restraint configurations were determined for various impact velocities. Based on these criteria, two types of deployable systems were designed and constructed, one an inflatable system and the other a rigid sliding system. These prototype systems then underwent a test and development program using anthropomorphic dummies and an impact sled. The test program evaluated the effectiveness of the head restraint systems under high- and low-speed crash simulations.