Testing of Reflective Markers for Indicating the Threshold and Centerline of Runways for Small Airports

Technical tests were performed to investigate the usefulness of retroreflective markers in improving runway threshold and centerline identification at small airports. During the hours of darkness, retroreflective markers were more effective in indicating the centerline than was the painted centerline. Retro-reflective markers were less effective in indicating the threshold than were the threshold lights.

These markers are not to be considered as a replacement for either the centerline or threshold lights. The effectiveness of the markers is a function of the intensity, location and aiming of the aircraft landing lights in relation to the line of sight of the pilot. The markers are inexpensive, easy to install and to maintain.