Opening or swing bridge sign: what it means
The opening or swing bridge sign warns of a bridge ahead that can open, for example to let boats through.
What does the opening or swing bridge sign mean?
Know your traffic signs lists it as “opening or swing bridge”. When the bridge is about to open, signals stop the traffic: alternately flashing red lights mean you must stop, as the Highway Code says for lifting bridges.
Quick quiz
What does the sign at the top of this page mean?
- A humped bridge ahead.
- A bridge ahead may open for boats.
- The road leads to a quayside or river bank ahead.
Show answer
B. A bridge ahead may open for boats. It warns of an opening or swing bridge ahead (Know your traffic signs). Source: Know your traffic signs: warning signs, GOV.UK; The Highway Code: light signals controlling traffic, GOV.UK; Traffic sign images, Department for Transport, GOV.UK
Where will you see it?
On roads over rivers, canals and docks.
What should you do?
Slow down and look for signals and barriers. Stop if red lights flash.
What do people get wrong?
Driving through as the red lights start to flash. Alternately flashing red lights mean you must stop.
Common questions
What do flashing red lights at a bridge mean?
You must stop. The Highway Code lists lifting bridges among the places with alternately flashing red stop lights.
Is it the same as a hump bridge?
No. A hump bridge sign warns of a steep rise in the road over a bridge.
Compare with
Hump bridge signA humped bridge ahead.
Quayside or river bank signThe road leads to a quayside or river bank ahead.
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 4 November 2026 against Know your traffic signs (warning signs) and The Highway Code (light signals).
- Know your traffic signs: warning signs, GOV.UK
- The Highway Code: light signals controlling traffic, GOV.UK
- Traffic sign images, Department for Transport, GOV.UK
Contains public sector information licensed under the Open Government Licence v3.0. Traffic sign images are Crown copyright, from the Department for Transport. Sources and image credits.