Active Lane Keeping Assist is a new safety feature making its debut on the CL-Class as part of the optional Driver Assistance Package. If the vehicle threatens to cross a continuous lane marking line, the system actuates an electric motor in the steering wheel, causing it to vibrate briefly - giving the driver a discreet but effective warning hint to countersteer immediately. The active system springs into action if the Mercedes coupe unintentionally crosses a continuous lane marking line to the right or to the left. In this case, the car intervenes by gently braking the wheels on the opposite side of the car, helping the driver to stay in the lane. Active Lane Keeping Assist is built upon the existing ESP® Electronic Stability Program.
Active Lane-Keeping Assist evaluates information provided by a camera mounted on the inside of the windshield. It identifies the contrast between the road surface and the lane markings. In addition, the optional radar system scans the side of the roadway for dividers and other roadway edge markings. The system also evaluates the driver's actions and can reliably determine whether the car is departing from the lane intentionally or not. For instance, there is no warning if the driver accelerates hard just before passing or when accelerating onto a highway, or if he brakes hard or steers into a curve.