An Insurance Institute for Highway Safety (IIHS) study found that the number of deaths of drivers in cars caught in side-impact crashes with SUVs dropped nearly 50 percent when automakers lowered the height of SUVs or added impact-absorbing bars below the front bumpers, according to an Associated Press report. The study, found the greatest benefit in design changes when a SUV strikes the side of a car. In such a case, the risk of a fatality dropped by 47 percent to 48 percent. For side crashes involving pickups and cars, the death rate dropped by 1 percent to 9 percent. In front-end collisions involving SUVs and cars, researchers found car drivers wearing seat belts were 18 percent to 21 percent less likely to die with SUVs meeting the guidelines. For car drivers failing to wear a seat belt, the risk was only reduced by 2 percent to 3 percent, showing the benefit of wearing safety belts. Fifteen automakers, representing nearly all of the U.S market, voluntarily agreed in 2003 to improve the compatibility between vehicles by September 2009 amid concerns that SUVs or pickups dangerously ride up atop cars in crashes and threaten passenger compartments. The changes involved redesigning the front-end of SUVs and pickups to better match up with the bumpers of passenger cars, and improving head protection by installing side air bags. When a redesigned pickup struck a car in a head-on collision, the number of deaths of belted car drivers declined 9 percent to 19 percent. For unbelted car drivers hit by pickups without the changes in a head-on crash, the death rate was about the same. The study, which examined car driver death rates from 2001 to 2004 involving 2000-2003 models of SUVs and pickups, was the first to examine death rates in cars involved in crashes with SUVs and pickups that comply with the agreement versus vehicles that do not yet meet the guidelines. About six in 10 new models of SUVs and pickups now have the design changes and experts expect it to take several years before older vehicles that lack the design are no longer abundant on the road.