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

See also:
Switching off automatically
The system switches off and the LED goes out:
After approx. 33 ft/10 m when driving forward.
Above approx. 9 mph/15 km/h when driving
forward.
Switch on the system again if necessary. ...
New suspension, xDrive intelligent all-wheel drive, and made-to-measure
dynamics.
The new BMW X3 features standard xDrive intelligent all-wheel drive. Now in
its third generation, BMW xDrive has been revised to incorporate even more
flexibility, quicker response and improved ha ...
Indicator/warning lamps
The indicator and warning lamps can light up in
a variety of combinations and colors.
Several of the lamps are checked for proper
functioning and light up temporarily when the
engine is starte ...
