Lane departure warning alerts you that your car is about to veer out of lane and warns you to get back into lane.
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.
By design, the lane departure warning system also doesn’t alert you if you have your turn signal on, or (some cars) if you apply the brakes.
