See also:

Switching off automatically
System switches off: above approx. 9 mph/ 15 km/h. Switch on the system again if necessary. ...

Low beams
Switch position with the ignition switched on: the low beams light up. ...

Camera monitoring: Lane Departure Warning System and Collision Warning
The Lane Departure Warning System available for the new BMW 3-Series Sedan is activated at speeds above 70 km/h (43 mph) and warns the driver if he unintentionally strays out of his lane. The syst ...