The concept
The parking brake is primarily intended to prevent the vehicle from rolling while parked; it brakes the rear wheels.

See also:
Brake force display
The concept
▷ During normal brake application, the outer
brake lamps light up.
▷ During heavy brake application, the inner
brake lamps light up in addition. ...
Switching off automatically
System switches off: above approx. 9 mph/
15 km/h.
Switch on the system again if necessary. ...
Remove unnecessary cargo
Additional weight increases fuel consumption. ...
