No U-turn to the left
Drivers must not make a U-turn to the left at this point. The prohibition applies at the location where the sign is posted. Foreign drivers should note that U-turn rules in Thailand are sign-specific, so a U-turn is only permitted where a sign or road marking explicitly allows it.
Verified as Thai road sign บ.7 from Thai Department of Land Transport sign series on 2026-05-15.
Study guide
Connect this sign to practice
No U-turn to the left is a "don't", and the Thai exam likes to probe the until-when part: where the prohibition lifts, what overrides it, and whether common driver workarounds are still legal. Practising it in context makes the answer obvious.
Now see it in questions.
Spotting No U-turn to the left 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.
