How does the active lane assist system work in the Audi A8?

I want to know more about how the active lane assist system functions in the Audi A8. Does it use cameras, sensors, or other technology? Is it always on or does it need to be turned on manually?

The active lane assist system in the Audi A8 uses a camera mounted on the windshield to monitor lane markings. It can detect when the car is drifting out of its lane and will gently steer the car back into place. It can also provide haptic feedback through the steering wheel to alert the driver. It is always active and can be turned off manually if desired.