A lane change assist system and method are provided for assisting the driver of the vehicle in maneuvering a lane change. The system includes a range sensor mounted on a vehicle for sensing range to an object in a side detection zone adjacent to one side of the vehicle. The system also includes a controller for determining when the side detection zone is clear for the vehicle to change lanes based on the sensed range signal. The controller determines whether there is sufficient space to initial a lane change maneuver based on the sensed range signal and generates an output signal indicative thereof. An output is provided to warning lights indicative of the determined state for initiating the lane change maneuver.