CONCEPT TOOK YEARS TO GAIN ACCEPTANCE OF AUTO INDUSTRY

Air bags are an idea whose time took a long time coming.

First tested in the 1950s, they were ready for use by the 1970s, but automakers successfully resisted government attempts to mandate them.

But in 1990, all new cars sold in the U.S. were required to be equipped with either automatic seat belts or driver's-side air bags.

Last year, about half the new cars sold in the country had driver-side air bags. By 1995, they will be offered in virtually every new car sold.

A good number of these also will offer front-seat passenger-side air bags. Twenty-four percent of highway deaths occur to the occupant of the passenger-side of the front seat, while 70 percent occur in the driver-side.

The air bag will deploy in a frontal collision involving forces equal to hitting a solid barrier at 12 mph (or a parked car at 25 mph).

The real effectiveness of air bags won't be known until data is collected after several years of widespread use. But General Motors Research Laboratories projects that air bags will prevent 20-40 fatalities out of 100 that would have occurred if the air bag had not been in place.

Car manufacturers advise that air bags cannot take the place of a lap/shoulder belt. It is projected that an air bag alone would prevent about 17 percent of car crash fatalities. The effectiveness of lap/shoulder restraints in preventing fatalities is put at 41 percent.

The addition of an air bag to a lap/shoulder restraint is expected to prevent an additional five fatalities out of 100 that would have occurred and avoid an added 10 serious injuries.