The traffic merges from the left sign features a main vertical arrow with a smaller angled arrow joining from the left within a red warning triangle.
It is commonly placed on slip road approaches to dual carriageways or expressways to warn drivers on the main road of merging vehicles.
What this sign means
This sign warns main-road drivers that vehicles on an adjacent slip road will join and merge from the left ahead.
- Red warning triangle border
- Large main-road arrow with smaller joining arrow
- Warns of merging traffic streams
What to do when you see it
Check your mirrors, assess traffic on the slip road, and adjust your speed or change lanes to the right if safe to do so.
- Create spaces for merging traffic where safe
- Avoid sudden heavy braking on the main carriageway
- Check right mirrors before changing lanes to let vehicles in
How this sign is tested
Theory questions focus on slip road priority rules, lane changing procedures, and safe speed adjustment when traffic merges.
Common mistakes
Assuming joining drivers will stop, or failing to check mirrors before swerving into the right-hand lane to make room.
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
Who has priority: main road traffic or merging traffic?
Main carriageway traffic has priority, but drivers should cooperate to allow smooth zip-merging.
Must I move into the right lane when I see this sign?
Only if it is completely safe to do so; otherwise adjust speed in your current lane.
Is this sign the same as a dual carriageway slip road sign?
Yes, it is standard on dual carriageway approaches to warn of merging slip roads.