Because of the large weight differences that now exist between heavy trucks and cars, car occupants are at risk of serious injury when they collide with large trucks. However, although there is little that can be done to reduce this disparity in weight, it is possible to modify trucks so that the effects of the impact between a heavy truck and a car could be lessened. This paper estimates the effects of modifying the fronts of heavy trucks to incorporate crushable structures with stiffness characteristics similar to the fronts of cars. Equations of motion are developed that show that equipping trucks with crushable zones would increase the deceleration distance available to car occupants in car-truck collisions by 40 percent and reduce the average deceleration to restrained occupants by a factor of 1.4. A method is provided that transposes this reduction in acceletation to a reduction in fatality risk using Fatal Accident Reporting System data for 1977-1985. An example is given that shows a crushable zone could reduce the likelihood of fatal injury to car occupants by as much as 33 percent.