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

I am interested in the active lane keeping assist feature in the Audi A8. Can someone explain how it works and how effective it is in keeping the car in its lane?

The active lane keeping assist in the Audi A8 uses a combination of cameras and sensors to detect lane markings and actively steer the car to keep it in the center of the lane. I have personally used this feature and found it to be extremely effective in highway driving.