Buick RIVIERA 1993 Manual page 36

Where is the air bag?
When is an air bag expected to inflate?
The air bag is designed to inflate in moderate to severe
frontal or near-frontal crashes. The air bag will only
inflate if the velocity of the impact is above the designed
threshold level. When impacting straight into a wall that
does not move or deform, the threshold level for most
GM vehicles is between 9 and
14 mph. However, this
velocity threshold depends on the vehicle design and
may be several miles-per-hour faster or slower. In
addition, this threshold velocity will be considerably
higher if the vehicle strikes an object such as
a
parked
car which will move and deform on impact. The air bag
is also not designed to inflate in rollovers, side impacts,
or rear impacts where the inflation would provide no
occupant protection benefit.
In any particular crash, the determination of whether the
air bag should have inflated cannot be based solely on
the level of damage on the vehicle(s). Inflation is
determined by the angle of the impact and the vehicle's
deceleration, of which vehicle damage is only one
indication. Repair cost is not a good indicator of
whether an air bag should have deployed.