How Lane departure warning system works
Lane departure warning alerts you that your car is about to veer out of lane and warns you to get back into lane.
That’s the basic idea, but there are several versions of the technology available now, including ones that react and steer away from the lane edge and even proactively keep the car centered. All forms of lane departure warning employ a low-cost camera mounted in the windshield near the rear view mirror that continuously watches the striped and solid lane markings of the road ahead. It is part of the circle of safety, the three most common and useful driver assists: protecting you to the front (adaptive cruise control and forward collision warning), side (lane departure warning), and rear side (blind spot detection).
The three flavors: warning, assist, self-centering
Lane departure warning. This is the original. It is a warning only. When you let the car drift near, onto, or over the lane marking, the car alerts you. As the driver, you have to take corrective action by steering the car back to the middle of the lane. It doesn’t work if the road has no lane markings. It may not work, or not as well, if your state waits until the lane markings are faded before repainting. Lane marking dots are sometimes harder to track, especially if their coloring has faded. If it’s raining or snowing, the camera may have trouble, too. By design, the lane departure warning system doesn’t alert you if you have your turn signal on, or if you apply the brakes.
Lane keep assist. This helps once you let the car drift too far. The car then steers itself away from the lane marking. The driver has to re-center the car in the lane. It’s also called lane keeping system, lane assist, side assist, lane departure alert with steering assist, or lane departure prevention.
Lane centering assist. This is the best and newest system, as long as you trust technology. It’s a fully proactive system. Lane centering assist always tries to keep the car centered in the current lane. It works as long as the car senses you have your hands at least lightly on the steering wheel, and as long as curves aren’t too sharp. If you have lane centering assist and adaptive cruise control, you have the beginnings of what some people would call self-driving. At the very least, the combination is enough to save you from inattentiveness if you speed along 5-10 seconds looking at a music playlist or scanning a full-screen text. “Lane centering assist” is not as well-established as the other two terms.
TIPS FOR USING
This feature relies on painted lane markings to operate. This feature is not designed to work with markers that are faded, covered, in disrepair, or are overly complicated.
If the roadway is covered with snow, leaves, fog or debris, the lane keeping assist may not be able to detect the lane markings on the road.
Turning your wheel will override this feature after it activates.