Sharp curve ahead
This sign warns that a sharp curve lies ahead. Reduce speed before entering the curve and keep to your lane throughout. Entering a sharp curve too fast is a common cause of loss of control, particularly on unfamiliar roads.
Verified as Thai road sign ต.4 from Thai Department of Land Transport sign series on 2026-05-15.
Study guide
Connect this sign to practice
Warning signs like Sharp curve ahead test whether you spot the hazard early enough to react. The Thai theory exam often pairs them with stopping-distance, visibility, and right-of-way questions, so practising the symbol alongside its scenarios makes the wording less of a trap.
Now see it in questions.
Spotting Sharp curve 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.
