Do Airbags Save More Lives than Seatbelts?
Takata inflator debacle raises questions no one dares ask
The count is now 10 deaths and more than 100 injuries globally, according to Automotive News, and potentially 25 million cars and light trucks in the U.S. alone (plus at least 9 million more in the rest of the world) need to be recalled so their Takata airbag inflators can someday, somehow be replaced. So far, Honda has been affected the most. Last year, the company replaced its president as a result of the safety scandal.
The National Highway Traffic Safety Administration already has fined Takata $70 million for its apparent reluctance to notify the agency of a defect that caused bags to shoot dangerous, sharp shrapnel. A consortium of 10 automaker clients of Takata has just determined that the root causes of the shrapnel misfires are the supplier's use of ammonium nitrate, plus the way Takata constructed the assembly, both combined with exposure to heat and humidity, Automotive News reported Tuesday. The airbag failures occur mostly in hot, humid climates, and after the bags have aged a few years.
The deaths and injuries could have been prevented, probably with a better construction method and had Takata used different materials and chemicals. But the defects raise another question, in my mind, at least: Are airbags as safe as we assume, for preventing death and injury in head-on car crashes?
For at least 25 years, the unequivocal answer has been "yes," even though there were some initial objections from enthusiasts (and, if memory serves, in some car magazines) as the U.S. auto industry made its transition from three-point belts, to those universally unloved automated belts, to ignitions that wouldn't engage without the driver's belt buckled, to single driver's airbags, and finally to driver/front passenger airbags.
We also discovered, in the early years of airbags, that they need to be dual-powered; that a standard, single-speed airbag can severely and even fatally injure a child or small adult. Joan Claybrook, the since-retired president of Ralph Nader's Public Citizen, who pushed for airbags as the Carter administration's NHTSA chief, once scolded automakers first for resisting airbags, then for installing unsafe airbags.
Enthusiasts once circumspect of the rush to an airbag mandate fell into lockstep and considered them necessary safety items for every new car. Airbags initially were meant to be a salve for the vast hordes of drivers and passengers who refused to wear their belts (something no true enthusiast ever had to be convinced to do), though by now, safety advocates including Claybrook insisted that the seatbelt and the airbag only worked safely as a pair.
Safety advocates, including Claybrook, launched a concerted effort to raise seatbelt usage by convincing states to sign seatbelt bills into law. It worked. Seatbelt usage is up significantly in this country, and so the belts can cover for any deficiencies from the airbags -- until now.
When a driver and his or her front-seat passenger, both wearing seatbelts, get into an accident in which the front airbags deploy, do you credit the seatbelts or the bags for preventing serious injury? I asked NHTSA for any data that might answer this question.
A NHTSA spokeswoman sent National Center for Statistics and Analysis Paper Number 500, dated 2001, which estimates that 4,138 lives were saved in the U.S. in 2000 when the drivers/passengers wore seatbelts and had airbags, 1,854 lives were saved by belts only and 548 lives were saved by airbags only.
"Because airbags are passive restraints, their effectiveness ratings reflect the protection provided by the airbag's presence, not its deployment," study author Donna Glassbrenner notes. "Note also that the effectiveness of a belt-bag system is somewhat less than the sum of the effectiveness ratings of its two components. …" The study says belts are 48 percent effective in preventing fatalities, while airbags are 14 percent effective. But added together, they're just 53.72 percent effective.
These are statistics -- or damned statistics -- of course, the result of mathematical equations designed to prove why something didn't happen. Which is not to say I'm advocating we start removing airbags from our dashboards. But the other eight or 10 airbags in a modern car seem more reliably safe than the ones designed to blow up in your face.
Side curtains, rollover airbags, and kneebags can prevent injuries that three-point belts can't mitigate. Mercedes-Benz's new E-Class has airbags in the sides of its seats that deploy when a collision is imminent, to push occupants toward the middle of the seat. Like Joan Claybrook yelling at you to sit up straight, the bags are designed to have your posture in the best possible position when the impact occurs. And that's where the belts' effectiveness can come in.
What we need is a more modern survey, or some tests, comparing the efficacy of belts when in cars and trucks with stiffer, more modern body structures, and accompanied by all those other types of airbags. Though we can easily blame the shrapnel problem on Takata's poor design and/or neglect, the bottom line is that after nearly three decades, we still can't count on an airbag to be as safe and effective as a simple, three-point seatbelt.