Regulatory sign
Lane open (green arrow) sign
What does the Lane open (green arrow) sign mean?
An overhead lane control signal: a green arrow means the lane below is open to traffic facing it.
Also known as: Lane control green arrow
What it means
This lane is open to you.
On some busy roads, lane control signals vary the number of lanes in each direction to suit the main traffic flow.
A green arrow above a lane means it is available to traffic facing the signal.
Where you'll see it
Above the lanes on roads with tidal flow lane control.
Rules to know
A green arrow indicates that the lane is available to traffic facing the signal.
Know Your Traffic Signs, p. 142
Common mistakes
Mistake: Ignoring the signals because the road looks normal.
Instead: Lanes change direction at different times. Follow the signal above your lane.
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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
Opposite
Lane closed (red cross)
Regulatory sign
The lane is closed.
See also
Move to the next lane (white arrow)
Regulatory sign
Move to the next lane on the left.
More regulatory signs
All regulatory signs
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- Know Your Traffic Signs (Department for Transport, Sixth edition, 2023), Tidal flow lane control signs and signals, p. 142
Sign image: Department for Transport, Traffic sign images (diagram 5001.1). © 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