Why Safety Belts Work
When you ride in or on anything, you go as fast as it goes.

Take the simplest vehicle. Suppose it is just a seat on wheels.

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.
See also:
Replacing Restraint System Parts After a Crash
CAUTION:
A crash can damage the restraint systems
in your vehicle. A damaged restraint
system may not properly protect the
person using it, resulting in serious injury
or even death in a crash. ...
Compass
The vehicle may have a compass
display in the Driver Information
Center (DIC). See Compass for more information. ...
Height Adjustment
Height Adjustment
Press and hold the top or bottom of
the switch to raise or lower the seat.
Release the switch when the
desired height is reached. ...
