Signal Heads, Displays, Pedestrian Signals and Signing
Signal heads and displays
Signal heads must be assembled with the correct housing, visor, backplate, lens, and mounting hardware. MUTCD Part 4 governs face placement, visibility, and displays; 12-inch lenses are required for new installations in many high-speed applications, and agencies often standardize on them. Backplates with retroreflective borders improve conspicuity. Verify the display sequence and that each face is aimed at its approach.
Pedestrian signals and signs
Pedestrian signals include countdown displays and, where required, accessible pedestrian signals with locator tone, vibrotactile indication, and speech. Push buttons must be reachable, generally 15–48 inches above the surface under ADA, with the agency’s height standard often about 3.5 ft. Signing includes street name signs, regulatory signs, crosswalk markings, and stop lines.
Worked example: On a 45 mph approach, a plan shows an 8-inch lens. The standard requires a 12-inch lens for new work at that speed. Changing the lens is not just a lens swap: check that the housing, visor, and backplate accept the larger door, that the head remains centered over the lane, and that the bottom height still meets clearance. If the existing head cannot accept the 12-inch door, replace the head. The reasoning is that lens size, door size, and mounting geometry are one assembly, not independent parts.
Traps: visor installed on the wrong side; missing backplate; pedestrian signal aimed at the wrong crosswalk; push button behind the ramp landing; sign mounted too low; mismatched lens and door.