prohibition sign
No overtaking
Thai road sign บ.4 — No overtaking. Meaning: Overtaking another vehicle is prohibited on the road section where this sign is posted. 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: ป้ายห้ามแซง
Independent English reference · Source: Department of Highways · Sign บ.4
Road response
On the road
Driver action
What should you do?
Overtaking another vehicle is prohibited on the road section where this sign is posted. Drivers must remain behind vehicles ahead until the restriction ends or an end-of-restrictions sign is posted.
Exam-style scenario
Read the situation
A slow truck is ahead on a two-way road, but this sign stands beside the centre line before you consider passing.
Best response: Remain behind the truck throughout the signed restriction instead of crossing out to pass it.
Sign comparison
Don’t confuse it
This sign
No overtaking
Compare with
No-overtaking zone
Key difference
The red-ring sign directly prohibits overtaking from its position; the yellow no-overtaking-zone panel warns that a restricted zone begins.
Put sign knowledge into practice.
Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.
