Road Signs | Width or Height Restriction

Max headroom - DOT530
A warning sign indicates, in imperial units, the maximum headroom under a bridge or other overhead obstruction. There may be an additional sign showing the height in metric units. These signs may be sited well in advance of a bridge, with the distance, either in yards or miles, shown on a plate; this may have an arrow to indicate that the bridge is on a side road at a junction ahead.