Dip ahead
A dip in the road surface lies ahead. Reduce speed before reaching it to maintain control of the vehicle. Dips can be sharper than they appear, so exercise caution even on roads that look flat.
Verified as Thai road sign ต.37 from Thai Department of Land Transport sign series on 2026-05-15.
Study guide
Connect this sign to practice
Dip ahead is a hazard cue, not a rule. On the Thai exam that distinction matters. Run a few questions to see how the scenario gets framed: which way to slow, who has priority, and what the next sign is likely to be.
Now see it in questions.
Spotting Dip 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.
