Abstract
This report summarizes the information on design and testing of two instruments that have been developed to avoid painting over reflective raised pavement markers. The two devices were developed by the California and Ohio Departments of Transportation. The California instrument optically scans the roadway for reflective surfaces whereas the Ohio one consists of a mine detector type metal sensor to denote the presence of a marker. Both devices will automatically cut off the flow of paint in front of a marker and turn it back on just past the marker.