Warning sign
Safe height plate sign
What does the Safe height plate sign mean?
Shows the safe height beneath electrified overhead cables, usually at a railway or tramway. Taller vehicles must not pass.
Also known as: Safe height under cables
What it means
The safe height beneath the overhead electric cables ahead.
The plate is used with the overhead electric cable warning sign. It gives the safe height beneath the cables.
If your vehicle or its load is taller, do not go under the cables.
Where you'll see it
On the approach to electrified railways and tramways that cross the road.
Rules to know
Electrified overhead cable and the safe height beneath it (usually associated with an overhead electrified railway or tramway).
Know Your Traffic Signs, p. 29
Common mistakes
Mistake: Forgetting the height of the load.
Instead: Know the full height of your vehicle and load.
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© Crown copyright. Free to reuse under the Open Government Licence v3.0, as long as the sign is reproduced accurately and not in a misleading context.
Related signs
Used with
Overhead electric cable
Warning sign
The warning sign the plate goes with.
See also
Height warning bells
Warning sign
Bells that warn tall vehicles.
More warning signs
All warning signs
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- Know Your Traffic Signs (Department for Transport, Sixth edition, 2023), Level crossing signs and signals, p. 29
Sign image: Department for Transport, Traffic sign images (diagram 780A). © Crown copyright, reused under the Open Government Licence v3.0.
Last reviewed 11 October 2026. This page explains the sign in our own words; for the full rules, see The Highway Code. How we source and check content