The rate of death in motor vehicle accidents depends very much upon the nature of those in the accident. The overall average in the United States is currently just under 12 percent. In accidents when a car going 30 miles an hour hits a pedestrian, the rate increases to 20 percent. Accidents involving large trucks make up about 6 percent of accidents, but about 11 percent of traffic fatalities, usually causing the death of those in the other vehicle.