The side impact airbags are designed to inflate inmoderate to severe side crashes. A side impact airbagwill inflate if the crash severity is above the system’sdesigned “threshold level.” The threshold level can varywith specific vehicle design. Side impact airbags arenot designed to inflate in frontal or near-frontal impacts,rollovers or rear impacts, because inflation would notlikely help the occupant. A side impact airbag willonly deploy on the side of the vehicle that is struck.In any particular crash, no one can say whetheran airbag should have inflated simply because of thedamage to a vehicle or because of what the repair costswere. For frontal airbags, inflation is determined bythe angle of the impact and how quickly the vehicleslows down in frontal and near-frontal impacts. For sideimpact airbags, inflation is determined by the locationand severity of the impact.What Makes an Airbag Inflate?In an impact of sufficient severity, the airbag sensingsystem detects that the vehicle is in a crash. For boththe frontal and side impact airbags, the sensing systemtriggers a release of gas from the inflator, whichinflates the airbag. The inflator, airbag and relatedhardware are all part of the airbag modules inside thesteering wheel, instrument panel and the side ofthe front seatbacks and behind the rear seatbacksclosest to the door.How Does an Airbag Restrain?In moderate to severe frontal or near frontal collisions,even belted occupants can contact the steering wheel orthe instrument panel. In moderate to severe sidecollisions, even belted occupants can contact the insideof the vehicle. The airbag supplements the protectionprovided by safety belts. Airbags distribute the force ofthe impact more evenly over the occupant’s upperbody, stopping the occupant more gradually. But thefrontal airbags would not help you in many typesof collisions, including rollovers, rear impacts, and manyside impacts, primarily because an occupant’s motionis not toward the airbag.Side impact airbags would not help you in many typesof collisions, including frontal or near frontal collisions,rollovers, and rear impacts, primarily because anoccupant’s motion is not toward those airbags.Airbags should never be regarded as anything morethan a supplement to safety belts, and then onlyin moderate to severe frontal or near-frontal collisionsfor the driver’s and right front passenger’s frontalairbags, and only in moderate to severe side collisionsfor the side impact airbags.1-55
