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New Report on Auto Industry Data Shows Automakers Misled NHTSA and Public When Denying Link Between Roof Strength and Injuries

March 30, 2005

New Report on Auto Industry Data Shows Automakers Misled NHTSA and Public When Denying Link Between Roof Strength and Injuries

NHTSA Is Poised to Propose New Roof Strength Standard

  WASHINGTON, D.C. – Auto industry data show that automakers have misled government regulators and the public for years by claiming that roof strength and injuries in rollover crashes are unrelated, a new report says.

 The report, written by Martha Bidez, Ph.D., of Bidez Associates, and a professor of biomedical engineering at the University of Alabama at Birmingham, debunks what some auto manufacturers have said for years: that in rollover crashes, people sustain head and neck injuries when they dive into the roofs of their vehicles, not when the roofs crush into the people’s heads. Automakers have made this claim to argue against government requirements for stronger roofs on vehicles and to shield themselves from liability in lawsuits brought by families of rollover crash victims.

But Bidez’s report, “Roof Crush as a Source of Injury in Rollover Crashes,” analyzes Ford’s own tests to show that roof crush does, in fact, occur prior to injurious neck loads during rollovers.  Thus, improving a vehicle’s resistance to roof crush would prevent catastrophic head and spinal cord injuries and deaths. Her report is particularly important because the National Highway Traffic Safety Administration (NHTSA) is on the verge of proposing a new roof strength standard, although auto safety experts do not expect it to improve safety in a meaningful way. The current standard dates from 1971 and has not been updated despite repeated promises by agency officials to do so.

 In addition, new industry documents made public only recently show that while Ford has denied a link between roof strength and rollover crash injuries, its subsidiary, Volvo, has recognized that strengthening roofs and installing side head air bags and pre-tensioned belts in rollover crashes will save lives. Volvo produces the XC-90, a vehicle with a roof that does not crush in during rollover tests.

Every year, almost 10,000 people are killed in rollover crashes, and 6,000 to 7,000 deaths a year are related to roof collapse and roof crush. 

 “Strengthening roofs and installing other basic safety devices, such as side head air bags, safety glass and pre-tensioned belts, is the only way to save lives in rollover crashes,” said Public Citizen President Joan Claybrook. “For automakers to claim that head injuries are the fault of people ‘diving’ into the roofs of their cars is ludicrous. If the roofs don’t collapse in a rollover crash, the people in the vehicle have a far better chance of surviving. The industry should strengthen roofs.”

 Added Bidez, “This report presents the results of some of the industry’s own rollover test data as unequivocal evidence that roof crush can and does cause catastrophic injury and death.   It underscores the urgent need for a significantly upgraded dynamic roof strength standard to protect belted occupants in rollovers.”

 The report also shows that:

  • Ford misrepresented the meaning of its data in presentations to NHTSA;
  • The dynamic tests done by Ford demonstrated consistent results that could be repeated with dynamic tests when viewed in the framework of occupant injury and correlated with real-world data on rollovers;
  • Neck position is a crucial component of how severely injured someone is in a rollover crash, yet Ford arranged the neck position of its dummies in some of its published studies, which produced misleading results on the impact on the spinal cord of roof crush; and
  • Any investigation of roof strength and rollover crashes should analyze total harm to occupants, not just deaths.

 The current roof crush standard was enacted in 1971 and took effect in 1973. The one-sided static test requires one section of a vehicle’s roof to withstand 1.5 times the vehicle’s weight. The test assumes the windshield remains intact throughout the crash, despite the fact that in rollover crashes, the windshield is usually gone by the first quarter turn. Once gone, the roof loses a third of its strength, making it far more likely that the roof will crush in and making it easier for people to be ejected.

 Over the years, NTHSA officials have promised many times to upgrade the standard and require automakers to make stronger roofs. But the agency has dragged its feet and has not issued a rule. The agency is expected to propose a minor upgrade – a placebo – to respond to demands for stronger vehicle roofs. It is not known whether the agency will address pre-tensioning of belts in rollovers. Currently, there is no federal test for belt performance in rollovers. Side head air bags are the subject of a separate rulemaking, but it does not address inflation in rollovers.

 One of the basic tenets of auto safety is that to prevent injuries, there can be little or no intrusion. It is essential to prevent parts of the vehicle from closing in and coming into contact with occupants in the vehicle, Claybrook said. Other key injury prevention techniques involve padding and adequate restraint systems. So by strengthening roofs and ensuring that they stay intact during rollover crashes – and installing side head air bags, safety glass in side windows and pre-tensioned belts, which keep occupants in their seats – many of the deaths and injuries that occur in rollover crashes can be prevented, she said.

 “The auto industry has misled NHTSA and the public solely to protect its bottom line. But in doing so, it has jeopardized the lives of thousands of motorists every year,” Claybrook said. “NHTSA should not allow itself to be hoodwinked any longer. Automakers know how to increase survivability in rollover crashes, as the documents show. NHTSA needs to require all manufacturers to follow suit.”

 Bidez is submitting her report to the docket at NHTSA. A copy of the report is available by clicking here.