The driver's and front passenger's airbag are triggered in certain frontal collisions Fig. 1. Further airbag systems may also be triggered, depending on the circumstances.

When the system is triggered, the airbags fill with a propellant gas and open out in front of the driver and front passenger Fig. 1. In order to provide the desired extra protection in an accident, the airbags have to inflate extremely rapidly (within fractions of a second). The fully deployed airbags cushion the forwards movement of the front occupants and help to reduce the risk of injury to the head and the upper part of the body.

Special openings in the airbag allow the gas to escape at a controlled rate to restrain the forward movement of the occupant's head and torso. Once the impact has been absorbed, the airbag deflates sufficiently for the front occupants to see forward.