Mandatory sign
Turn left ahead
Blue circular signs are mandatory: they tell you what you MUST do. A white arrow shows the direction you are required to take -- here, turn left ahead.
When you see it
- ◆ Follow the direction shown by the arrow -- it is compulsory.
- ◆ Blue circles instruct; red circles prohibit.
- ◆ Get into the correct lane in good time.
- ◆ It is used to keep traffic flowing in the required direction.