mandatory sign
Turn left only
Thai road sign บ.43 — Turn left only. Meaning: Drivers must turn left at the junction ahead and must not go straight or turn right. 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: ป้ายให้เลี้ยวซ้าย
Independent English reference · Source: Department of Highways · Sign บ.43
Road response
On the road
Driver action
What should you do?
Drivers must turn left at the junction ahead and must not go straight or turn right.
Exam-style scenario
Read the situation
Your lane reaches a junction with this blue arrow, although your route planner suggests going straight.
Best response: Ignore the straight-ahead route suggestion and turn left as required by the lane sign.
Sign comparison
Don’t confuse it
This sign
Turn left only
Compare with
Turn right only
Key difference
The mandatory arrow bends left and allows only that turn; the mirrored arrow requires a right turn.
Put sign knowledge into practice.
Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.
