SUV rollover rates improving, study says

WASHINGTON — Automobile manufacturers have made strides in designing sport utility vehicles that are safer and more resistant to dangerous rollover crashes, the government's top highway safety official said Wednesday.

Dr. Jeffrey Runge, administrator of the National Highway Traffic Safety Administration, said new research released by the agency found that SUVs have become less top-heavy since 2000, calling it "a dramatic increase in rollover resistance."

Runge attributed much of the improvement to manufacturers' development of smaller, car-based utility vehicles called crossovers.

Runge, releasing new government rollover tests, said two dozen SUVs from the 2005 model year earned a four-star rating in their review, representing a vast improvement compared with one vehicle that received a four-star rating in 2001.

No SUV earned a five-star rating.

Under the government's ratings for rollovers, a vehicle with five stars has a rollover risk of less than 10 percent while a four-star vehicle has a 10 percent to 20 percent risk. Three-star vehicles have a 20 percent to 30 percent risk.

Rollover crashes are considered extremely dangerous. While only 3 percent of all crashes involve rollovers, they lead to more than 10,000 deaths every year, about a quarter of all traffic fatalities. About 60 percent of fatalities in SUVs involve rollovers.

Among SUVs, the Ford Freestyle 4-by-4 was rated the best among the four-star vehicles with a 13 percent chance of rollover. It was joined by the Chrysler Pacifica, which earned the same score in 2004 and was not retested because it had no significant changes to its structure.

Among pickup trucks, the Chevrolet Colorado 4-by-4 and its corporate twins, the GMC Canyon, Dodge Dakota 4-by-4 and the Dodge Ram 1500 4-by-2, all received four stars with a 17 percent chance of rollover.

Runge warned it would take 25 years for the fleet of SUVs and pickups to turn over toward the newer designs, many of which feature technologies that help reduce accidents, such as electronic stability control.

NHTSA predicts a vehicle's chance of rollover in a single-vehicle crash through a laboratory measurement that assesses how top-heavy a vehicle is and the results of a test that examines how it responds when it trips over a curb or shallow ditch, the most common cause of rollovers.