The second study by IIHS5
examined two types of fatality rates for 1- to 4-year-old case
vehicles during CY 2000-2001 and during 2008-2009 in the United States. In both study
periods, case-vehicle occupant fatalities per million registered case-vehicle years in the
passenger vehicles were computed by case-vehicle type and curb-weight category (500 lb
increments). Fatalities to occupants of other cars that collided with these case vehicles in twovehicle
crashes were also computed per million registered case-vehicle years by case-vehicle
type and weight category. In both study periods, occupant fatality rates generally declined with
increasing curb weight for each type of vehicle. And overall, occupant fatality rates declined for
all vehicle and weight categories between these time periods, with SUVs experiencing the
greatest declines compared with cars and pickup trucks. Fatality rates in other cars in twovehicle
crashes declined over time for all vehicle categories, but more steeply for SUVs and
pickup trucks colliding with cars than for cars colliding with cars. This second study
acknowledges the difficulty of identifying the specific contribution of the EVC agreement to the
long-term reduction in fatality rates, but believes that the large reductions in car-occupant fatality
rates when cars collide with LTVs indicate the likely benefits of the EVC agreement.