The Impact of State Variations in Vehicle Mix: The Impact on Traffic Fatalities

The Capstone team measured the impact of variations in the vehicle population across the United States. In 1975, Congress passed the Energy Policy and Conservation Act in order to decrease dependence on foreign oil. As part of that Act, the government imposed Corporate Average Fuel Economy (CAFE) standards on passenger cars sold in the United States, which effectively set the goal of doubling the average fuel economy of these vehicles by 1985 to 27.5 miles per gallon. These standards did not apply to light trucks, which only made up about 10 percent of the vehicle population when the law was enacted. Today, light trucks account for almost 50 percent of the registered vehicles in the United States. Researchers have concluded that passenger cars have become consistently lighter over the last thirty years in response to CAFE standards. The team’s research looked into whether the increased presence of the heavier light trucks sharing the road with lighter passenger cars has increased the risk of death for the nation’s drivers.