Abstract: An apparatus for locating, inspecting, or placing marks on a roadway. The apparatus includes a GPS-based machine vision locator for sampling discrete geographical location data of a pre-existing roadway mark evident on the roadway. A computer may determine a continuous smooth geographical location function fitted to the sampled geographical location data. And a marker is responsive to the GPS-based locator and geographical location function for replicating automatically the pre-existing roadway mark onto the roadway. The apparatus is typically part of a moving vehicle. A related method is disclosed for locating, inspecting, and placing marks on a resurfaced roadway. A similar apparatus can be used to guide a vehicle having a snow plow along a snow-covered roadway, or a paving machine along an unpaved roadway surface.