Hazard clearance markers are required at each corner of a bridge when there is an obstruction that could be hit by an oncoming vehicle. Obstructions include blunt ends of concrete parapets, old pipe or timber railing, guide rail terminated at the bridge ends parallel to traffic, bridge structure members, culvert headwalls, etc. When standard approach roadway guide rail is not attached to the bridge railing directing vehicles across the bridge, hazard clearance markers are usually required.
To properly install the hazard clearance markers:
1. Place the markers directly in front of the obstruction to oncoming traffic.
2. Keep the inside edge (closest to traffic) of each marker directly in front of the inside edge of the obstruction.
3. Install the signs so that the bottom of the sign is 3’-5’ above existing ground.
4. There are left and right side markers. The diagonal lines should always go down and inward toward the roadway.
Here is a photo of properly installed signs at the blunt end of the concrete bridge parapet:
Here is an example of incorrect placement. In this photo, the left side hazard clearance marker is being used for the right side: