Buick Regal 2011 Owner's Manual page 53

3-10 Seats and Restraints
Put someone on it.
Get it up to speed. Then stop the
vehicle. The rider does not stop.
The person keeps going until
stopped by something. In a real
vehicle, it could be the windshield...
or the instrument panel...
or the safety belts!
With safety belts, you slow down as
the vehicle does. You get more time
to stop. You stop over more
distance, and your strongest bones
take the forces. That is why safety
belts make such good sense.