Roadway narrows ahead on the left side
The roadway narrows from the left side ahead. Reduce speed and keep clear of traffic affected by the narrowing lane edge.
Verified as Thai road sign ต.23 from Department of Rural Roads sign series on 2026-05-15.
Study guide
Connect this sign to practice
Most candidates can describe Roadway narrows ahead on the left side. The Thai exam tests whether you can pick it out of a roadside scene under time pressure and choose the right response. Practising it inside the question flow is what closes that gap.
Now see it in questions.
Spotting Roadway narrows ahead on the left side 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.
