Lack of attention or fatigue may cause you to leave the lane without noticing. The system uses a camera to detect whether solid lane markings are unintentionally crossed. A haptic warning is issued to the driver by vibrating the steering wheel in pulses. If there is no reaction, Active Lane Keeping Assist can guide the vehicle back into the lane by braking on one side. The brakes are applied whenever solid lines are unintentionally crossed. If there is driver activity or a turn signal is detected, the system does not intervene from the outset.