2009 GMC Acadia Owner's Manual - Page 21

Seats and Restraint System 1-17 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.