Temporary traffic-control sign
Right lane merges left
Thai road sign ตก.20 — Right lane merges left. Meaning: The right lane merges into the through lane on its left. 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: ป้ายเตือนเบี่ยงเบนการจราจร
Independent English reference · Source: Department of Highways · Sign ตก.20
Road response
On the road
Driver action
What should you do?
The right lane merges into the through lane on its left. Reduce speed before the signed condition and keep enough space to respond safely.
Exam-style scenario
Read the situation
The right lane terminates at the works and its traffic must merge into the lane on the left.
Best response: Signal and merge from the ending right lane into a safe gap in the continuing left lane.
Sign comparison
Don’t confuse it
This sign
Right lane merges left
Compare with
Right lane closed in work zone
Key difference
Its lane line tapers into the continuing left lane, describing a merge; the lane-closed sign announces a blocked right lane ahead.
Put sign knowledge into practice.
Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.
