The Drive Assist package combines the camera-based systems Lane Departure Warning and Approach Warning with City Brake Activation.
The Lane Departure Warning detects lane markings and alerts the driver to an unintentional lane change at speeds above approx. 40 mph by means of vibrations in the steering wheel. The warning is not activated if the lane change is deliberate, that is, when the indicator has been activated.
Whereas the Approach Warning with City Brake Activation detects vehicles, the Person Warning reacts to pedestrians. If a vehicle ahead suddenly brakes, the BMW responds immediately if the Approach Warning is activated. The system operates in steps. A warning symbol is first displayed, then the symbol begins blinking and an acoustic warning is emitted, and finally the brakes are applied.
The person warning operates at speeds between 6 and 37 mph and emits a single-level warning in the event of acute danger. If the system warns of a potential collision, the brakes are simultaneously preconditioned for a faster response.
In the event of an emergency, the system applies the brakes, although this function can be limited by darkness and fog. An attentiveness assistant monitors the driver's steering response for signs of tiredness and displays a message in the control display suggesting the driver take a break in the event of irregular driving behaviour.