IIHS Debuts New Roof Strength Rating System

The Insurance Institute for Highway Safety (IIHS) launched a new roof strength rating system that will evaluate the way vehicles protect their occupants in rollover crashes. According to the new rating system, vehicles that receive the "good" rating "must have roofs that are more than twice as strong as minimum federal safety standard require," the organization said in a statement for the press.

In essence, the roofs are evaluated with the help of a metal plate that hits a certain side of the roof at a constant speed. "To earn a good rating, the roof must withstand a force of 4 times the vehicle's weight before reaching 5 inches of crush," IIHS explained. The ratings pretty much depend on vehicle weight which is mainly based on the overall weight of the engine, the transmission system as well as the 4-wheel drive system, if available.

"Our research shows that a strength-to-weight ratio of 4 reflects an estimated 50 percent reduction in the risk of serious and fatal injury in single-vehicle rollover crashes compared with the current federal standard of 1.5," says Institute president Adrian Lund.

IIHS has already tested twelve small SUVs, with four of them receive the top rating of good. Volkswagen Tiguan received the highest rating, thus providing the strongest roof among the ones tested, while Kia Sportage only received a "poor" rating.

"It's not surprising that Volkswagen and Subaru earn good ratings in our new roof test because these automakers were among the first to ace our front and side tests," Lund points out.

According to figures provided by the Institute, approximately 10,000 people die every year in rollovers which underline the need for stronger and more efficient roofs. Obviously, a stronger roof protects passengers from being thrown through windows, doors or windshields and provide additional safety to those who don't use the seatbelt.