One-way straight ahead
Traffic on the road ahead must travel straight in the direction shown by the arrow. Drivers must not drive against the one-way direction.
Verified as Thai road sign บ.37 from Thai Department of Land Transport sign series on 2026-05-15.
Study guide
Connect this sign to practice
One-way straight ahead is a "do this" sign, but the Thai exam will phrase it as "what's the legal action here". Same answer, different angle. Practising the wording of the question, not just the symbol, is what closes the gap.
Now see it in questions.
Spotting One-way straight ahead in isolation is one thing. Recognising it inside a real exam-style question, among lookalikes and trick wording, is another. The diagnostic mixes it in for you.
