Crumple Zone

The passenger cell is made stiff, while the zones in front of and behind it collapse in a controlled way. Crash boxes behind the bumper beams absorb low-speed impacts and are designed to be replaced. Modern bodies use different steel grades for each zone. Independent crash test programmes evaluate how well the structure protects occupants. Electric cars use crumple zones too, and the battery is placed in a protected area inside the structure.

Deformation lengthens the time of the impact and reduces the forces on the occupants.

After a crash, damaged crumple-zone parts must be repaired according to the manufacturer's instructions, not just straightened. A badly repaired car may not protect occupants as designed.