Warning Sign/Maximum Headroom
Maximum Headroom Under Arch Bridges
|Maximum Headroom Under Arch Bridge|
|TSRGD ref :||531.1A|
|Common Plates :|
These signs warn drivers of the lowest passable point of an arch bridge. These must now be accompanied together, (in the past, the imperial sign was permitted by itself), but the metric sign is not authorised for use alone. Signs may be incorporated into direction sign to warn drivers of the restriction and to alert them of an alternative route.
All bridges with a clearance of less than 16 feet 6 inches (about 5 metres) are normally signed. Both regulatory roundels and warning triangles can be used, depending on the type of bridge.
Signs will be mounted above the portal to the bridge, and will have a white band that shows the width of the road where the maximum safe headroom is. If vehicles rooves extend to the sides of the bridge, there may be extra signs and bands that extend over that section of carriageway.
If particular bridges are prone to strikes, there will be yellow and black bands that border the portal.