In conclusion, the analysis of fatality rates yielded a statistically significant positive
effectiveness for PEAS and SEAS in crashes between light trucks and cars as a whole. But the
results of this analysis are inconsistent for pickup trucks and SUVs and are also not fully
corroborated by the non-parametric analysis. The somewhat more positive results from the
tables observing exclusively front-to-side impacts are encouraging because it is the type of crash
where higher effectiveness would be expected, but even here, the result for pickup trucks is not
positive, let alone significant. The analysis on the body frames of SUV/CUVs still leaves open
the question regarding the wide difference between the percent effectiveness of the SUVs and the
pickups. Overall, the results fall short of permitting an unequivocal conclusion that the
technologies introduced upon LTV certification have reduced fatality risk to car occupants.
Nevertheless, these results can be reconciled with the study recently released by IIHS.
That study is strong evidence that fatality risk to car occupants in impacts by late-model light
trucks has declined in absolute terms over the past decade, and, in particular, that pickup trucks
and SUVs have become less aggressive over time, relative to cars. However, that study did not
analytically isolate or quantify specific factors accounting for the decline. It may be due to a
combination of compatibility improvements in the light trucks; crashworthiness improvements in
the cars; crash avoidance technologies; and changes in vehicle mix, vehicle use, driving patterns,
or the overall decline in fatality risk for all vehicles. Furthermore, the compatibility
improvements in the light trucks are not limited to those involved in certifying to the voluntary
standard, but could include any prior or subsequent modifications. By contrast, our results try to
address exclusively the fatality reduction due to compatibility improvements close to the time of
self-certification, and it is this limited effect that falls short of being unequivocally significant.