A pre-impact inflation air bag system for a vehicle having a preselected
decreasing distance between the vehicle and an object is disclosed. The
system comprises a plurality of nested inflatable air bags. A plurality
of inflators are provided for inflating the plurality of nested
inflatable air bags, respectively. A collision sensor produces a
collision sensor output upon detecting the object with the preselected
decreasing distance between the vehicle and the object. A controller
receives the collision sensor output for simultaneously inflating each of
the plurality of nested inflatable air bags between vehicle and an
object. A plurality of pressure relief members are connected to the
plurality of nested inflatable air bags for sequentially deflating the
plurality of nested inflatable air bags upon sequential impact of the
plurality of nested inflatable air bags with the object.