Though it is intended to save them from injury or worse, many motorists resent the "interlock" system on 1974 cars, which prevents the engine from starting until the driver and all front-seat passengers have buckled their seat belts. Impressed by the volume and vehemence of constituent mail on the subject, House members voted two weeks ago 339 to 49 to tack onto a Department of Transportation appropriations bill an amendment that would kill the requirement that cars be equipped with an interlock system (and also the annoying buzzer that sounds when a seat belt is unfastened; only a warning light on the dashboard would be required). So far as the debate disclosed, not many Congressmen realized that the amendment also would damage the prospects of what promises to be a much more effective safety device: the air bag.
Air bags are designed to inflate on impact in any crash at a speed of 12 m.p.h. or more, filling a car's front passenger compartment to hold the driver and passengers in their seats, then deflate in seconds after the impact is over. The Department of Transportation wants to make them mandatory on cars beginning with the 1977 model year; the amendment would permit the department only to require that they be offered as an option.
The difference is critical. Even mass-produced as mandatory equipment, air bags would be costly: perhaps $200 a car. If produced only in limited numbers as an option, they would be still more expensive; Ford Motor Co. President Lee Iacocca figures that they might sell for $335 a car. Allstate Insurance Co., in full-page newspaper ads last week deploring the congressional action, said that "only the well-to-do" could afford the price of optional bags. It urged the Congress to reverse the measure and make bags mandatory.
Test Miles. Automakers contend that test data are still insufficient to prove the safety and reliability of air bags. Transportation Department experts disagree. They contend that hundreds of accidents involving air-bag-equipped autos have conclusively shown that bags protect drivers from serious injury even in high-speed crashes. They also claim that tests have banished two early fears about the bags: that they would inflate accidentally when there was no collision, and that they might pop open with such force as to injure children. In millions of test miles driven, that just has not happened. The bags do have some drawbacks: they do not inflate twice, so if a car strikes another and caroms off to hit a guardrail or a third vehicle, the driver would be protected against the second crash only if he was also wearing a seat belt. But the evidence seems to warrant making the bags mandatory.
That still is likely. The House bill must go to conference with the Senate, which passed a bill that said nothing about either belts or bags. The probable result is a compromise under which the seat belt-interlock system would be banished, but the mandatory air bag would be retained.