Seymour Cray, the thomas edison of the supercomputer, liked to stay on the cutting edge of technology. So successful was his quest to create an ever-faster computer that during the cold war, the U.S. Department of Defense regarded him as a national security resource.
But one September afternoon in 1996, at the age of 70, Cray fell victim to a far clunkier machine. He was driving a sport utility vehicle in Colorado Springs when a car swerved and rammed his left rear door. Cray's SUV spun counterclockwise and rolled over three times. Although he was wearing a seat belt, the crash broke his neck and he died of severe head injuries two weeks later. "The irony of Seymour Cray's death was that supercomputers were used early on in the auto industry to simulate the crush characteristics of vehicles," says Carl E. Nash, an adjunct professor of engineering at George Washington University and a former chief of the accident investigation division of the National Highway Traffic Safety Administration (NHTSA). "Through his work, Cray contributed hugely to roadway safety, yet he got himself killed in a type of vehicle that seems to defy that."
Rollover deaths are startlingly common events, resulting in nearly a third of the 35,806 passenger fatalities from traffic accidents in 1999. Any car can turn over, but SUVs are much more likely to do so, a fact given national attention recently by the reported failures of Firestone tires on Ford Explorers. That controversy brought to light disturbing statistics. According to the NHTSA, more than 60 percent of SUV occupants who died in traffic accidents in 1999 were involved in rollovers. By comparison, only 23 percent of all car occupants who died were involved in rollovers. "Fundamentally, most SUVs are working trucks with station wagon bodies grafted onto them," says Nash, who has worked as a consultant in lawsuits concerning SUV stability. "From the aspect of physics, they're simply the wrong type of vehicle to have on the road."
Rollovers are a leading cause of auto-related deaths, accounting for 10,857 fatalities in 1999, and SUVs are three times as likely to roll over as other cars. The problem is part physics— SUVs have high centers of gravity— and part perception: SUV drivers don't realize how fast they're going or how vulnerable they are.
At the same time, of course, SUVs are hugely popular. A decade ago, light trucks and vans accounted for just 20 percent of all vehicles. Now they account for a third and are expected to number half within a decade. "We're talking about the vehicle that will soon be in the majority," says Clay Gabler, an associate professor of mechanical engineering at Rowan University in Glassboro, New Jersey. "Any problems we see now will only magnify, and everyone— automakers, safety testers, and researchers like myself— is struggling to catch up with that fact."
