Turn left ahead sign: what it means
The turn left ahead sign means you must turn left at the junction ahead. If the symbol is reversed, you must turn right ahead.
What does the turn left ahead sign mean?
It is a blue circle, so it is an order. Know your traffic signs describes it as “turn left ahead (right if symbol reversed)”. Plates can add exemptions or more detail.
Quick quiz
What does the sign at the top of this page mean?
- You must turn left at the junction ahead.
- You must go the way the arrow points.
- Pass on the left of the island or bollard.
Show answer
A. You must turn left at the junction ahead. Turn left ahead (right if the symbol is reversed), an order shown by a blue circle (Know your traffic signs). Source: Know your traffic signs: regulatory signs, GOV.UK; The Highway Code, rule 109, GOV.UK; Traffic sign images, Department for Transport, GOV.UK
Where will you see it?
Before junctions where only one way out is allowed, such as where the road ahead is one-way towards you.
What should you do?
Get into the left-hand lane in good time, check your mirrors and signal, and turn left at the junction. You must obey signs that give orders (rule 109).
What do people get wrong?
Turning left too early, into a driveway or side road before the junction the sign means.
Common questions
What is the difference between turn left ahead and turn left?
Turn left ahead tells you to turn at the junction coming up. The turn left sign, with a straight arrow pointing left, is placed where you must go left now.
Can buses go straight on?
Only if a plate under the sign exempts them.
Compare with
Turn left signYou must go the way the arrow points.
Keep left signPass on the left of the island or bollard.
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
Checked on 3 November 2026 against Know your traffic signs (regulatory signs) and The Highway Code rule 109.
- Know your traffic signs: regulatory signs, GOV.UK
- The Highway Code, rule 109, 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.