In the long and convoluted history of airbag rulemaking and litigation, the latest issue to spark controversy involves the National Highway Traffic Safety Administration's (NHTSA) decision to lower the speed of rigid-barrier crash testing with unbelted dummies. Public Citizen and others filed suit in federal court against the agency, claiming the decision to require manufacturers to conduct airbag compliance tests at 25 mph instead of 30 mph "could result in hundreds of additional fatalities" because the airbags wouldn't provide sufficient protection to occupants of all sizes in serious crashes.
From the start, the Institute supported NHTSA. The consequence of returning to 30 mph testing with unbelted dummies "is a probable increase in airbag power, which would pose additional risks," the Institute told the court.
Now the U.S. Court of Appeals for the District of Columbia has weighed in, siding unanimously with NHTSA. The agency's "selection of twenty-five miles per hour is both supported by the record and rationally explained," the court ruled.
Why 25 mph is the better choice
The higher the speed at which a crash test is conducted, the greater the force that's needed to quickly inflate an airbag. An airbag with the inflation force necessary to restrain an unbelted crash test dummy at a speed as high as 30 mph would be likely to injure an occupant in a real-world crash who's very close to the airbag when it begins to inflate. This is what the Institute told the court in the brief it filed in support of NHTSA (see "Unbelted crash test speed is subject of legal challenge," March 15, 2003).
On the other hand, reducing the speed of compliance tests with unbelted dummies to 25 mph allows automakers to equip vehicles with airbags that inflate with less force and, therefore, pose less risk of inflation injury.
"Contrary to Public Citizen's claims, research indicates that depowered airbags are providing effective protection in serious crashes," Institute president Brian O'Neill says. "At the same time, there's less risk of inflation injury in crashes at lower speeds. It's a win-win."
O'Neill adds that he hopes "the court's ruling will help put this issue of 25 versus 30 mph testing to rest, so we can get on with other highway safety priorities."
Basis of the court's decision
In challenging the test speed of 25 mph, Public Citizen made two main arguments. One was that NHTSA violated congressional directives under the Transportation Equity Act for the 21st Century. But the court disagreed, pointing out that "nowhere does [the statute] say anything about the particular vehicle-testing requirements NHTSA must adopt, much less the speed the agency must use in its unbelted rigid barrier crash test."
In response to Public Citizen's second argument, which claimed that NHTSA was arbitrary and capricious in choosing the 25 mph speed for compliance testing, the court responded this way: "NHTSA explained, reasonably in our view, why a twenty-five mile per hour unbelted test speed, considered in the context of the entire rule, serves the agency's overall safety goals."
O'Neill agrees with the court, saying "it was clear back in 2000 when NHTSA decided to go with 25 mph testing that this would serve overall safety goals. Now it's even clearer because accumulating evidence from real-world crashes indicates that depowered airbags are effective."
According to a number of recent studies, the airbags in newer vehicles are protecting people of all sizes in serious crashes. At the same time they're contributing to a reduction in airbag-related deaths.