A study was conducted by selecting cases from available NCSS/NASS data on nearside crashes involving fatal chest and abdominal injury. Twenty-five cases indicated over-involvment of older front-seat occupants in multi-vehicle side impact crashes (76% more than 50 years old and 28% more than 70 years old). Analysis of the 1975-86 Fatal Accident Reporting System (FARS) confirmed that older occupants are over-represented in nearside crashes with an incidence of 64% more than 50 years old and 36% more than 70 years (as compared to 26% more than 50 and 8% more than 70 respectively for single vehicle frontal crashes). The individual case study also showed that 88% of the multi-vehicle nearside crashes were at intersections and that the driver of the struck vehicle frequently caused the crash by driving error (52%) or traffic violation (17%). The majority of the cases occurred in daylight hours and on dry roads. Alcohol use was not a factor. Changes in visual perception, judgement and attention in the older driver may be factors in crash causation. In terms of automotive design, improvements in side interior padding should aim at safety of older occupants because of their high involvement in this crash type. The analysis raises further questions about the validity of the NHTSA proposed test dummy and injury criterion (SID - side impact dummy, and TTI - thoracic trauma index) because the dummy develops high, nonhuman-like forces and the injury criterion is sensitive to both protective and unprotective padding. Although an analysis of photographs from the side-impact vehicles indicated that 44% of the crashes had side-structure deformation that was similar to that produced in the NHTSA moving deformable barrier test, only 24%-32% of the cases actually addressed the proposed dynamic test. (A) For the covering abstract of the conference, see IRRD 837684. This paper was also published in the proceedings of the 33rd Annual Conference of the Association for the Advancement of Automotive Medicine, Baltimore, Maryland, October 2-4, 1989, p337-52 (see IRRD 826472).
Abstract