Dual Carriageway Ends vs Traffic Merges from the Left
When it comes to UK road signs, the devil is often in the detail. Two signs that frequently confuse learners are “Dual Carriageway Ends” and “Traffic Merges from the Left.” At first glance, they look like they could mean the same thing — but they don’t.
Let’s clear it up so you’ll never get caught out in your theory test or on the road.
Dual Carriageway Ends
- Appearance: A white triangle with a red border showing two black arrows narrowing into a single roadway.
- Meaning: The dual carriageway is coming to an end, and you’re about to continue on a single carriageway.
- Why it matters:
- On a dual carriageway, the national speed limit for cars is 70 mph.
- On a single carriageway, it drops to 60 mph.
- You’ll lose the safety of the central reservation, which means an increased risk from oncoming traffic.
Memory tip: Triangle = warning. This sign is warning you about the road layout ahead.
↖️ Traffic Merges from the Left
- Appearance: A white rectangular sign with a bold arrow and a shorter line joining from the left.
- Meaning: Traffic will merge into your lane from the left.
- Why it matters:
- You may need to adjust your speed or road position to let vehicles merge safely.
- It isn’t a “give way” or junction — it’s a smooth blending of traffic streams.
- Where you’ll see it: On a motorway or dual carriageway
Memory tip: Rectangle = information. This sign is telling you about traffic behaviour, not a change in the type of road.
✅ Key Difference
- Dual Carriageway Ends = warning about the road layout changing (dual → single).
- Traffic Merges from the Left = information about other vehicles joining you.
One is about the road itself, the other is about traffic flow.
Final Thought
For learners, these signs are a classic example of why paying attention to shapes is just as important as recognising the symbols inside them:
- Triangles = warnings about hazards or changes in the road ahead.
- Rectangles = information to help you drive safely alongside others.
Get those basics clear, and you’ll not only sail through the theory test, but also feel more confident handling real-world traffic situations.