Consequently, the industry is sticking by a commitment to beef up testing of side airbags even though there is a lack of evidence that they pose the same risk as front airbags, especially to children.
"So far the information looks pretty good," said Adrian Lund, referring to early studies of side airbag deployments. He is senior vice president of the Insurance Institute for Highway Safety and chairman of the auto industry panel that wrote voluntary guidelines for testing side airbags.
The guidelines grew out of a 1999 challenge by the National Highway Traffic Safety Administration. After the front airbag crisis, NHTSA said automakers ought to prove new safety devices, such as side airbags, don't create new risks.
The panel, which included automakers and airbag suppliers, completed the guidelines about 15 months ago. Car companies promised to phase them in as they design airbag systems for new models. The tests mostly entail firing the side airbags with child-sized dummies in a variety of positions.
The side airbag situation is widely viewed as an important test case for whether the industry can regulate itself when it is introducing new technologies. Other technologies, such as telematics, are on the horizon.
Mick Scherba, director of General Motors' safety and crashworthiness center, said the guidelines are not much different from what GM was doing on its own. He says they demonstrate the industry's willingness to do what's right without regulation.
Some are not convinced. Joan Claybrook, president of the consumer group Public Citizen and a proponent of government regulation of side airbags, was preparing last week to state her views to Dr. Jeffrey Runge, the new NHTSA administrator. She declined to discuss specifics.
Because side bags are not mandatory and frequently are offered as options, not as standard equipment, the number in use is difficult to determine. But it is definitely growing.
Gloria Bergquist, vice president of the Alliance of Automobile Manufacturers, estimates side airbags are in 15 million to 20 million vehicles.
While the industry says it is testing to head off a problem or err on the side of safety, there may be other dangers.
Mark Levine, a safety specialist at DaimlerChrysler, told the panel he is concerned that overly stringent guidelines could lead to airbags that aren't potent enough to provide protection in side-impact crashes.