Speed limit signs
Remember that in areas of street lighting (other than on motorways) a 30 mph limit applies unless another limit is specifically signed.
The maximum |
The national |
speed, in miles per |
speed limit for |
hour, at which |
the type of road |
traffic may travel, |
and class of |
if it is safe to do so |
traffic applies |
A larger sign indicates the start of a speed limit. Smaller repeater signs act as reminders. Repeater signs for a 30 mph limit are used only on roads with no street lighting. Repeater signs for the national speed limit are used only on roads with street lighting (other than motorways)
Road marking used in conjunction with upright signs to indicate the speed limit
Entrance to a zone where a 20 mph speed limit is enforced by traffic calming measures (there may be no 20 mph repeater
signs within the zone)
End of 20 mph zone and start of 30 mph speed limit
Start of a speed limit at the boundary of a town or village
Start of motorway regulations, including the national speed limit (unless a different speed limit is signed)
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speed limit signs
Point on a road with street lighting where an existing 30 mph limit originally ended but has subsequently been extended (temporary sign). This sign alerts drivers that a previous higher limit has been replaced by a 30 mph limit by the removal of speed limit signs
End of road works and any temporary speed limit through those works (may be supplemented by a sign indicating the permanent speed limit beyond the road works)
Reminder that enforcement cameras are in use (may be supplemented by a speed limit sign)
Maximum speed advised, in miles per hour, at a bend (the plate may be used with other warning signs)
Area where speed cameras are in use
Speed camera nearby on a lit road with a 30 mph speed limit (i.e. where there are no speed limit repeater signs)
Minimum speed permitted, in miles per hour, unless it is impracticable or unsafe to comply
Length of road where two cameras are used to measure the average speed of a vehicle between two points
Speed camera nearby on an unlit road subject to the national speed limit (i.e. where there are no speed limit repeater signs)
End of minimum speed requirement
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Low bridge signs
Each year there are hundreds of incidents in which bridges are struck by vehicles too high to pass under them. Both rail and road users have been killed in these incidents. Look out for signs in this section and make sure that you are not a bridge basher.
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.
Bridges particularly at risk from strikes may have a variable message sign that is activated by high vehicles passing through an infra red beam. When the sign is activated, four amber lamps flash, the top pair alternating with the bottom pair.
Regulatory signs
No vehicles |
No vehicles |
over the height |
over the height |
shown may |
shown may |
pass the sign |
pass the sign |
(height shown |
(height shown |
in metric and |
in imperial |
imperial units) |
units) |
At non arch bridges mandatory signs may be used; it is unlawful for an overheight vehicle to pass one of these. They are placed on the bridge and at the side of the road in front of the bridge.
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low bridge signs
Advance warning of a mandatory height restriction ahead; the sign may include an
arrow, if the restriction is on a side road
Location of mandatory height restriction ahead, with indication of an alternative route
Warning signs
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.
Chord markings used indicate the points between which different headrooms over different parts of an arch bridge are available.
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The maximum safe headroom at an arch bridge is shown on the triangular warning signs. Road markings guide high vehicles
through the highest part of the arch. Drivers of all vehicles should give way to oncoming high vehicles in the middle of the road when there is insufficient room to pass. Drivers of cars and other low vehicles may keep to the left hand side of the road, crossing the road markings, where this would enable them to pass oncoming vehicles in safety.
To improve the conspicuity of a bridge, black and yellow bands may be added to the arches or beams and to the abutments.
Where reduced headroom over a road is due to an overhanging building or
structure, a plate may be added below the warning triangle to indicate this (“building” may be varied to “buildings” or “structure”).
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low bridge signs
Signs incorporating height restriction roundels and warning triangles
Roundels or warning triangles will sometimes be incorporated into directional signs that may also indicate an alternative route to take to avoid the low bridge.
Roundels may also be incorporated into road works signs to indicate temporary height restrictions.
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