warning sign
Roundabout ahead
Thai road sign ต.21 — Roundabout ahead. Meaning: A roundabout lies ahead. Learner-manual coverage: this identity is shown in the current DLT car-driver learner manual. Inclusion does not mean it appears in every theory test.
Thai name: ป้ายเตือนวงเวียนข้างหน้า
Independent English reference · Source: Department of Highways · Sign ต.21
Road response
On the road
Driver action
What should you do?
Reduce speed and prepare to follow roundabout priority and lane discipline.
Exam-style scenario
Read the situation
A roundabout is hidden beyond the next bend and circulating traffic is not yet visible.
Best response: Reduce speed before the hidden roundabout and be ready to yield at its entry.
Sign comparison
Don’t confuse it
This sign
Roundabout ahead
Compare with
Roundabout
Key difference
The yellow diamond gives advance warning before the roundabout; the blue circular sign controls the circulation at the roundabout itself.
Put sign knowledge into practice.
Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.
