Visibility and Shielding
All signal faces, including pedestrian signals, should be equipped with visors to reduce reflected glare from the sun or other light, and to direct the signal indication to the approaching traffic. Cut-away visors are the most commonly used.
Full circle and tunnel type visors further reduce the possibility of signal indications being seen by opposing traffic. Louvered visors or optically programmed lenses are the best type of shielding to help prevent signal indications from being seen by opposing traffic.
Signal heads should be fitted with a backplate to improve their visibility by making the head stand out from the surroundings and by helping to prevent confusion due to advertising signs and the rising or setting of the sun. The use of backplates enhances the contrast between the traffic signal indications and their surroundings for both day and night conditions, which is also helpful to older drivers.