Width restriction ahead (2.5 metres)
A width restriction of 2.5 metres is ahead. Vehicles wider than 2.5 metres must not proceed through the restricted section. Foreign drivers should note that vehicle width includes mirrors and any load extending beyond the body.
Verified as Thai road sign ต.31 from Thai Department of Land Transport sign series on 2026-05-15.
Study guide
Connect this sign to practice
Width restriction ahead (2.5 metres) 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 Width restriction ahead (2.5 metres) 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.
