Abstract: A contouring machine control system, contouring/smoothing method, and kit for enabling a contouring machine to automatically contour three-dimensional surfaces includes a contouring member, such as a screed or dirt grading blade, a target either attached to the contouring member or located at a remote location, a tracking device at the other of the contouring member or remote location that tracks the target and measures the position of the target in three dimensions, a proximity sensor adjacent one end of the contouring member to detect its height above a physical reference, and a controller/computer for controlling the height of the two ends of the contouring member. One of the ends is controlled as a function of a stored profile of the desired surface to be contoured and the target or tracking device position, while the second end is controlled as a function of the current height of the proximity sensor above the reference.