The knee airbag system is designed so that the airbag for the driver is triggered in some (but not all) types of frontal collision.

If the front airbags are triggered in a frontal collision, the driver's knee airbag will also be triggered if the impact threshold stored on the control unit is exceeded.

When the system is triggered, the airbag is filled with propellant gas and inflated between the lower part of the dash panel and the driver Fig. 1.

Although the airbag is not a soft cushion, it can absorb the energy of an impact and thus help to reduce the risk of injury to the lower limbs.

All this happens in a fraction of a second and many people are not even aware that the airbags have been triggered. Airbags are released with considerable force. For the protection of occupants, it is important that no objects are in the path of the airbags when they are inflated.

When the seat belts are worn correctly, fully inflated airbags will retard and restrain the forward movement of the occupants, thus helping to reduce the risk of injury.