mandatory sign
One-way right
Thai road sign บ.39 — One-way right. Meaning: Traffic on the road ahead must travel to the right in the direction shown by the arrow. Learner-manual coverage: this identity is shown in the current DLT car-driver learner manual. Inclusion does not mean it appears in every theory test.
Thai name: ป้ายเดินรถทางเดียวไปทางขวา
Independent English reference · Source: Department of Highways · Sign บ.39
Road response
On the road
Driver action
What should you do?
Traffic on the road ahead must travel to the right in the direction shown by the arrow. Drivers must not enter or continue against that one-way direction.
Exam-style scenario
Read the situation
A blue right arrow governs the one-way road you are about to enter.
Best response: Follow the blue arrow to the right and join the one-way road in its permitted direction.
Sign comparison
Don’t confuse it
This sign
One-way right
Compare with
One-way left
Key difference
The blue arrow sends one-way traffic right across the junction; the mirrored companion arrow sends it left.
Put sign knowledge into practice.
Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.
