This report documents the results of an analysis of the effect of car weight on safety. The analysis encompasses a number of crash modes including fatality risk in single vehicle nonrollover crashes, serious injury and fatality risk in car-to-car crashes, and serious injury risk in collisions of cars with medium/heavy trucks. This work was undertaken as part of an effort to study the long-term effects of the major reductions in passenger car weight of the 1970's and 1980's. Data from the State of Texas for accident years 1984 through 1987, and from the State of Maryland for accident years 1984 through 1988 were used. The analysis employed logistic regression methods to model the conditional risk of serious injury as a function of a number of accident-level and person-level covariates. An important finding is that in car-to-car crashes, the change in injury rate associated with the reduction in vehicle fleet weight from 3,700 to 2,700 pounds has been estimated from the Texas data to be an additional 14 percent. The Maryland data produced an estimated increase in the serious driver injury rate of 4 percent for the shift from a 3,700 to 2,700 pound average fleet weight.
Samenvatting