In-depth investigations of car crashes in New South Wales have shown that head impact with car interior walls is a chief cause of death of lap/sash seat belt wearers. A project is reported in which the headspace requirements of a lap/sash seat belted car occupant were determined and compared with the head space availability of some modern cars. Crash simulations were employed to map the head space required by a 50th percentile male occupant wearing a lap/sash seat belt in an Australian sub-compact car. An anthropomorphic dummy represented the occupant; its kinematics were validated by head excursion data extracted from the results of tests, on human volunteers, reported in the literature. Three 1975 model cars were tested for head space availability and were found to be inadequate. Head impact countermeasures were investigated. The results provide evidence of the value of increased head space in reducing the incidence of head impacts sustaining by seat-belted car occupants. Head protection by impact attenuation is required in existing cars.
Abstract