DETROIT -- Acknowledging for the first time that sport utility vehicles pose special dangers to other motorists in crashes, automakers say that they are modifying the vehicles to make them less hazardous.
General Motors says it will make the 2002 Oldsmobile Bravada, GMC Envoy and Chevrolet Blazer with steel rails up to 2 inches lower inside their underbodies to reduce the risk of their overriding cars' bumpers and doorsills. Ford Motor Co. plans to do the same for its Explorer, Expedition and Lincoln Navigator over the next two model years.
DaimlerChrysler says it is making several changes to the Dodge Durango's front end for the 2002 model year to make it, too, less likely to override cars in collisions.
Foreign automakers also are designing their sport utility vehicles to make them less likely to kill or injure occupants of other vehicles in crashes. When the Toyota Sequoia goes on sale this autumn, it will be equipped with impact-absorbing hollow bars below the bumpers to keep it from riding over cars in collisions. Ford recently added that feature to its huge Excursion as well.
Nissan has just reinforced the bumpers on the 2001 Pathfinder, with the goal of spreading the force of an impact over a wider area of the struck vehicle, and plans further changes in coming years. Honda says it also plans design changes, although the company refuses to release any details.
Some of the changes, like the bars on the Toyota Sequoia, are being made purely for the safety of other motorists. Auto engineers say that some of the other changes are partly for safety and partly to improve the vehicles' ride and handling: Midsized GM sport utilities like the Envoy, for example, will no longer share underbodies with pickup trucks, so that they can be built with lower, lighter, less stiff frames that provide a more cushioned ride.
Even sport utility vehicles with the alterations will continue to pose risks to other motorists. They will remain considerably heavier than cars. And they will still have high hoods that cause more damage and injuries when striking cars from the side. Current sport utilities are almost three times as likely as cars to kill the other driver in a crash.
But after bitterly denying for three years that the design of sport utility vehicles made them unusually deadly to other motorists, auto industry officials now say that their designs cause up to half the extra deaths, and they are swiftly making changes.
"As the vehicle mix between pickups, minivans, vans, SUVs and cars has shifted in the U.S., automakers have recognized the importance of vehicle-to-vehicle crash compatibility," the Alliance of Automobile Manufacturers, the Washington-based trade group for domestic and foreign companies, said. "Tremendous progress has been made in a very short time."
A federal study estimated last year that the designs of sport utilities were causing 1,000 unnecessary deaths a year in other vehicles.
Dr. Hans Joksch, a longtime University of Michigan traffic safety expert who oversaw that study, estimated that the design changes now being made would eventually save 100 to 300 of those lives annually. But this improvement in safety will take time, he cautioned.