The effect of passenger load on unstable vehicles in fatal, untripped rollover crashes.

Consumers may be unaware of the risk of rollover crashes posed by passenger loads in vehicles with poor roll stability. This analysis demonstrates that certain sports utility vehicles and small pickup trucks have designs that are so unstable that the weight of the passengers in the vehicle affects its propensity to roll over. This effect occurs even though the weight of the loaded vehicle is less than the manufacturer's gross vehicle weight rating. The risk of a fatal, "untripped" rollover crash in vehicles with low roll stability is increased as each passenger is added to the vehicle load.