Road survey ahead
Survey crews are working ahead. The driver should slow down and watch for survey personnel and equipment on or beside the road.
Verified as Thai road sign ตก.1 from Department of Rural Roads sign series on 2026-05-15.
Study guide
Connect this sign to practice
Road survey 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 Road survey 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.
