What it is: Unibody passenger vehicles and many body-on-frame vehicles utilize specially designed front and rear areas that crumple or deform in a collision, helping to disperse energy.
How it works: A passenger vehicle's unibody is made of different sections of steel (or sometimes aluminum) welded into a single monocoque or unibody structure. Designed on computers and proven in the laboratory, special areas at the front and back of the unibody are specifically designed to bend, fold or otherwise deform in an accident. Body-on-frame vehicles often use a similar strategy in their body structures.
How it benefits the passengers: Crumple zones help slow the rate of deceleration for passengers, helping to reduce the chances of injury.