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A study of restraint use and effectiveness

In: HIT Lab Reports, Vol. 3, No. 8, April 1973, p. 1-25

Authors: F. Preston, R. Shortridge

Three related investigations are summarized: a determination of the demography of restraint use; a comparison of the incidence and severity of injuries for restraint users and nonusers; and a comparison of the incidence and severity of injury from those various areas in the vehicle that were contracted by the occupants. For the first part of the study restraint usage rates were compared for age groups, seat locations, and sex for selected mass accident files maintained by HSRI. Further comparisons were made for different values of speed, type of highway and drivers physiological condition, using the CPIR file. The results of these comparisons reveal that 16 to 22 year old drivers, drivers not using limit-access roads, and drivers who have been drinking are the least likely users of seat belts. Another aspect of this investigation was an evaluation of circumventing the seat belt buzzer system. A survey reveals that the most prevalent method is to keep the seat belt permanently buckled. Various accidents and injury related factors such as Vehicle Damage Index, speed at impact, accident configuration, rollover/nonrollover, seated location, and sex were controlled in the second part of the study. The percent injured and the Abbreviated Injury Scale for the overall body and selected body regions of restrained and unrestrained occupants were compared for various values of these factors. In general the results indicated that both the incidence and severity of injury is reduced for restrained occupants. The results of these comparisons, revealing how the pattern of injuries changes with different values of the controlled factors and how restraint usage affects these changes are presented.