THE QUARREL over the air bag is curiously passionate. It's true that the air bag provides extremely good protection to people in the front seat of an automobile in a head-on-crash -- a kind of crash that's usually catastrophic. It's also the only protection currently for those people, a large majority, who refuse to buckle their seat belts. But it's equally true that the government has only a limited responsibility to people who deliberately run obvious risks. The air bag has become the great symbol of the government regulation that attemps to save people from their own bad decisions.

There's a further curiosity: the air bag quarrel doesn't seem to have touched the larger issue of the passive restraint rule. A passive restraint is any device that protects you in a crash -- the adjective "passive" meaning that it works whether you chose to fasten a buckle or not. An air bag is one kind of passive restraint, and another is the automatic seat belt that fastens itself when you shut the car door. Over the next several years, all new cars are going to have to be equipped with one kind of passive restraint or another. You might think the automatic belt is a greater affront to the libertarian impulse than the almost invisible air bag -- but that isn't the way it has worked out.

What's emerging is, in fact, a classic of regulatory politics. As the rule now stands, it would apply to big cars first. Not unreasonably, the American manufacturers want the schedule reversed to apply first to the small cars -- since nearly all of the imports are small. Shortly before the election, legislation doing just that got most but not all of the way through Congress. That legislation would also have required several big companies to make the air bag available on at least one line of cars each.

That was a decent solution. It wouldn't have forced anybody to buy air bars. But it would have ensured that they were widely available to customers who wanted them. Now that solution is about to be tipped over. Rep. John Dingell (D-Mich.) is leading a campaign to strike out the air bag requirement altogether. It ought to be left to the market, he says, to decide what kind of passive restraints to put in cars.

Anyone who has followed the tale this far must wonder whether there isn't a better way to improve highway safety -- a way less tangled up in political ideology and less vulnerable to legislative sniping. Happily, there is indeed a better way. The transportation Department has been carrying out crash tests for most kinds of cars, both domestic and imported. It has published some of the results for some of the cars. Why not publish all of it? Why not publish, for all cars, crash safety ratings similar to the government's gasoline mileage ratings? Just a mileage ratings have increased the manufacturers' competition in fuel efficiency, crash ratings will create competition in safe design. For the years ahead, the greatest promise for safer automobiles lies not in tighter regulation of the producers, but in better comparative information for their customers.