Systematic automobile design for pedestrian injury prevention

About 7,800 pedestrians are killed annually in the United States and an estimated 300,000 are injured. There are 21 pedestrian fatalities each day, and these constitute 20% of the national auto fatality toll. It has been estimated that 4% of the automobiles coming off the production line (every 25th auto) will strike a pedestrian at some time. Relatively little systematic attention has yet been given to life saving and injury prevention for pedestrians by changes in vehicle design. In automobile design, some obvious pedestrian-injury agents such as hook-like door handles, protruding hinges and the more outstanding ornamental spears have been abandoned. In some cases rounded front surfaces have replaced sharp edges. Beyond such corrections (which have been by no means universal), the most frequent opinion is, "It's a 4,000 pound auto and a 150 pound pedestrian, and how can you change that?" or simply, "Aren't you just going to redistribute the injuries?" It is our thesis that pedestrian injury causation and prevention, although complex, is susceptible to logical analysis; that further methods of reducing pedestrian injuries and fatalities through vehicle design are still capable of being developed; that some of the general principles for such design are visible, and that specific designs can be prepared and tested for performance. The background for this discussion is the experience of pedestrian injury in New York City and Manhattan, the observations that can be made in that locality, and some of the general principles from passenger crash injury prevention. In many areas reliance is placed on the basic accident report and autopsy data collected by the Epidemiologic Research Division of Cornell Medical College, Dr. James McCarroll, Director. This data was collected with the cooperation of the Chief Medical Examiner of New York City, Dr. Milton Helpern, and the Accident Investigation Squad of the New York Police Department. Collection of the data by the Epidemiologic Research Division was made possible through a grant of the National Institutes of Health. The data include somewhat more that 230 consecutive pedestrian fatalities occurring in Manhattan during 1958 and early 1959. The basic data have simply been opened to the writer for study, so that he must take responsibility for conclusions, though some conclusions from Cornell analyses are also noted. In New York City, about 70% of all traffic fatalities are pedestrians, a figure typical of large Eastern cities. Among types of vehicles, automobiles accounted for 65% of the pedestrian fatalities in this series. Thus it is imperative that we make headway in passenger car design if we are to influence the largest portion of the fatalities which are occurring. There is no reason to think that automobiles are not the major factor in pedestrian injuries as well. There will be some important changes in the relative "mix" of the different variables of collision (such as speed) as compared to rural localities, but the physical relationship between the front of the vehicle and the human body is a constant. This analysis first classifies the observed causes of injury as they relate to the vehicle, to the surroundings, and to the different sequences in which the events of collision can develop. Then each class of injury is analyzed and general principles of design to reduce each type of injury are discussed. Conflicts that exist between some to the design approaches are then discussed. Two general approaches to the design problem are suggested, one for original design beginning with foundation principles and another an approach to redesign of existing vehicles by progressive testing.