Airbags were promoted as the next-generation lifesaver at a time when not everyone was using seatbelts (or more accurately, they were using them as seat belts, not safety belts). Prior to the airbag, the safety lobby was promoting an interlocking system that would prevent a car from starting unless the seat belt was fastened.
Once the airbags were introduced, it was immediately obvious that airbags alone were not enough. They now come with an "SRS," for Supplemental Restraint System, though, they were meant to be used in conjunction with seat belts. People still had to actively fasten a seat belt to gain the full protection afforded by the airbags.
The safety lobby convinced regulators that airbags must deploy quickly enough and with enough force to protect an unbelted adult male. Unfortunately, this force can kill children and small adults, mostly women. Interestingly, many of the children killed by airbag deployment were properly restrained in infant seats or with seat belts (in the front seat), the majority of those killed were un-seatbelted adults. Some automakers are incorporating a "smart seat" in which sensors automatically switch off the airbag if the occupant is small and light. Other carmakers have an airbag shut-off switch for the passenger seat airbag if the regular passenger in that seat is below a specified size, and for pick-up trucks which have no back seats.
Because of airbags, it is not recommended to ever have children in the front passenger seat, or to use that seat for buckling in a child or baby seat. Children should always be in the back seats, or in their mandatory child safety seats in the back seats, if below a certain size or age.
Recently, safety tests have shown that adding side airbags, which pop down from above the window, dramatically reduce injuries from side-impact collisions, particularly when a car is hit by a pickup truck or SUV with a high bumper