A study was conducted of how the fatality risk for a car driver in collisions between cars and light trucks or vans depended on certain characteristics of light trucks. The fatality risk was measured by the ratio of killed drivers to involved drivers. Information on killed drivers was taken from the Fatality Analysis Reporting System (FARS) and on involved drivers from the General Estimates System (GES). Because of incomplete information, cases from the Northeast and California could not be used. The fatality risk is influenced by vehicle weight, driver age, driver sex, speed limit, and other factors. Because these factors could confound the findings, mathematical models to adjust for their influence were developed. Without such adjustments, the fatality risk to a car driver in a collision with a sport utility vehicle (SUV) was 3.3 times as high as in a collision with a car; 2.6 times as high as in a collision with a pickup truck; and 2.3 times as high as in a collision with a van. After adjusting, these ratios were 1.6, 1.4, and 1.4, respectively. How these ratios depend on a vehicle design characteristic, using the height of the center of gravity from the ground and the forces the light truck exerted on the barrier in crash tests, was examined. Specifically, the average height of the force, the peak force, and the static and dynamic stiffness were measured in the test. Overall, the risk increased with the average height of the force, but it could not be determined whether this was a continuous increase, or whether exceeding a threshold was necessary. Stiffness showed a weaker, increasing relation with the risk, whereas peak power showed conflicting patterns. If the front of a light truck struck the left side of the car, the driver fatality risk always increased with the average height of the force; there were no apparent relations with other factors. In front-front collisions, no consistent pattern relating risk and characteristics of the light truck appeared.
Abstract