Rectangular blue or yellow advance warning signs indicate that one or more lanes on a motorway or multi-lane carriageway are closed ahead.
These signs give drivers early notice to move smoothly into open lanes before reaching maintenance zones or incidents.
What this sign means
The diagram displays vertical arrows representing open lanes, and broken or red-barred arrows representing closed lanes.
It warns of lane drops or closures caused by roadworks, broken-down vehicles, or lane management interventions.
- Red bar / broken arrow: Indicates lane is closed ahead.
- Straight vertical arrow: Indicates lane remains open.
- Distance plate: Shows distance remaining to the lane restriction.
What to do when you see it
Check mirrors early and signal your intention to merge into an open lane in good time.
Adjust speed smoothly and use zip-merging principles where appropriate to maintain steady traffic flow.
How this sign is tested
Theory test questions focus on early hazard identification and merging safely without cutting in aggressively.
Hazard perception clips assess early speed adjustment and mirror checks upon seeing lane closure warnings.
Common mistakes
Waiting until the last possible moment to swerve into an open lane.
Ignoring distance indicators and misjudging how far away the lane drop actually is.
Test yourself on this one
Road and traffic signs is the biggest category in the question bank with 102 questions, and signs turn up inside other categories too. Work through them free, no sign-up needed.
Practise road sign questionsFrequently asked questions
What should I do if my lane is closed ahead?
Move to an open lane as soon as it is safe to do so after checking mirrors and signaling clearly.
What does 'merge in turn' mean when lanes are closed?
Merge in turn encourages vehicles in adjacent lanes to merge alternately at the merge point during slow-moving queues.
Are speed limits reduced near lane closures?
Yes, lower advisory or mandatory speed limit signs often accompany lane closure warnings for roadworker safety.