Advertisement

Flimsy Roofs Lead to SUV Deathtraps

Share
Carl E. Nash, an adjunct professor of engineering at the National Crash Analysis Center of George Washington University, was formerly an executive of the National Highway Traffic Safety Administration

When Firestone tire failures leaped into public consciousness late last summer, Ford was quick to deny the culpability of its popular sports utility vehicle, the Explorer. Ford blamed Firestone for the rollovers--mostly in Explorers--that have left at least 148 people dead and severely injured many more.

Then, on Jan. 8, Ford finally accepted some responsibility, joining Firestone in a highly publicized announcement that it would pay an estimated $25 million to Donna Bailey to settle her lawsuit over an Explorer rollover that left her paralyzed from the neck down. GM refused to accept its culpability in a similar situation. On Jan. 19, after a three-month trial, a jury awarded more than $15 million to Robbie Lambert, who became a quadriplegic in a rollover crash of a Chevrolet Blazer.

Last month, the National Highway Traffic Safety Administration gave the Blazer a rollover-propensity rating of only one star (the worst). The Explorer got a dismal two stars (of a possible five).

Advertisement

But more critical is that what broke both Donna Bailey’s and Robbie Lambert’s necks were the force and speed at which the roofs of their SUVs collapsed. The jury in Lambert’s case ruled that the Blazer was defectively designed due to the weakness of its roof.

Long before the Blazer was conceived, auto makers knew how to make strong car roofs and why it was important to do so. Rollover test films dating back to the 1930s show roofs withstanding multiple impacts without collapsing. Ford’s narration of a 1960s film showing one of its station wagons rolling over said, “Note that even after two complete rollovers, full protection for the passengers is provided by the roof structure.”

Auto racing provides proof that a strong roof will protect occupants. Race car drivers have rolled their cars many times without serious injury because they have roll bars built into their roofs, effective safety harnesses and helmets. For less than $100, cars, SUVs, pickups and vans could have the equivalent of these features.

The steel structure of the Explorer’s roof weighs only about 100 pounds--less than 3% of its total weight. By adding less than 20 pounds of structure, and using good design and engineering practices, a car or SUV roof can become an effective roll bar.

Racing harness protection can be provided by ordinary safety belts that automatically tighten around an occupant when the vehicle rolls over; such belts have become common in new cars. All that is needed is a rollover sensor to trigger them. Interior padding in roofs, required in all new vehicles by federal standard, protects a person’s head like a racing helmet.

The number of rollover fatalities and serious injuries is growing with SUV sales and as parents pass their older SUVs on to their more accident-prone teenagers. GM’s and Ford’s SUV profits reportedly range from around $4,000 to more than $10,000 per vehicle. Is $100 of this profit too much for a major increase in customer safety?

Advertisement

Ford Motor Co. Chairman William Clay Ford Jr. has been quoted as saying he worries that his company could end up with a tobacco company’s reputation if it does not improve its SUVs. That is why Ford will soon offer air bags that deploy across the side windows of their SUVs. Ford also will offer electronic stability, or skid-control, systems that they expect to reduce the likelihood of a rollover.

But one of the least expensive and most effective ways to protect people in rollovers is to strengthen the roofs of new vehicles. If GM, Ford and the other auto makers did so, they could save most of the 11,000 people who are killed annually in rollovers.

General Motors’ fundamental excuse for the industry’s dangerous roof designs is based on a 1975 paper. In it, GM engineer Edward Moffatt argued that roof crush does not cause head or neck injuries in a rollover. He wrote that an occupant’s head is already in contact with the roof when the roof hits the ground so that further roof collapse does not cause injury.

GM then conducted tests to try to prove the Moffatt theory. Both the theory and the test interpretations were wrong: Actual roofs often collapse and buckle inward at a speed far greater than the speed with which the vehicle hits the ground.

Moffatt and others from GM testified in the Lambert case. However, Michael Piuze, Lambert’s attorney, showed that GM secreted and misrepresented test results and published misleading conclusions on the Moffatt theory. Donald Friedman, Lambert’s expert in the trial, testified that he had investigated 20 other cases where a Blazer roof buckled exactly as did Lambert’s, causing six fatalities, nine quadriplegias, two paraplegias and three brain injuries.

Auto makers should not wait for the government to order safer vehicles. They are responsible for making vehicles that protect their customers.

Advertisement
Advertisement