This report analyzes the effects of the Enhancing Vehicle-to-Vehicle Crash Compatibility
Agreement, generically abbreviated as EVC, which the vehicle manufacturers established in
2003 as a voluntary measure, as a means to reduce occupant fatalities of passenger cars in
crashes with pickup trucks or SUVs. Specifically, the report addresses the fatality reduction due
to compatibility improvements at the moment of self-certification, which varies by make and
model but, according to the EVC, would be sometime up to September 2009.
Under the compatibility agreement, voluntary standards for LTVs (pickup trucks, SUVs,
and vans) were agreed upon to reduce the height mismatches between these LTVs and passenger
cars. These measures were specifically aimed to reduce fatalities when the front of the LTV
contacts the side or the front of the car.
Based on data from both the Fatality Analysis Reporting System and R.L. Polk &
Company, the number of occupant fatalities in passenger cars in crashes with light trucks per
million light trucks registration-years was calculated for selected LTV makes and models. This
data was collected for each model’s last three model years before self-certification to the
compatibility agreement and also the first three model years after self-certification.
The evaluation methods in this report compared the overall fatality rates before and after
self-certification (main analysis) and the number of makes and models that had lower fatality
rates after self-certification to the number of models that had higher rates (supplementary nonparametric
analysis). The main analysis is similar to a 2008 evaluation of the compatibility
agreement by the Insurance Institute for Highway Safety, but it now includes additional model
years (1998-2009) and calendar years (2002-2010).
The principal finding is a statistically significant 8 percent reduction in car-occupant
fatalities after light trucks self-certified to the compatibility agreement. But the results are
inconsistent for pickup trucks and SUVs. The observed fatality reduction for pickup trucks is
negative (-5%) and not statistically significant, while for SUVs it is a positive and statistically
significant 17 percent. Furthermore, the non-parametric analysis does not show fatality
reduction for significantly more than 50 percent of the makes and models. Overall, these results
provide some evidence that the EVC has reduced fatalities but are not sufficiently strong to
permit an unequivocal conclusion that it has been effective in reducing fatality risk to car
occupants.