warning sign

Zipper merge ahead

Thai road sign ต.74 — Zipper merge ahead. Meaning: Traffic streams merge alternately ahead. 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: ป้ายเตือนการรวมช่องจราจรแบบสลับฟันปลา

Independent English reference · Source: Department of Highways · Sign ต.74

Road response

On the road

Driver action

What should you do?

Traffic streams merge alternately ahead. Adjust speed and merge in turn with vehicles from the adjacent lane.

Exam-style scenario

Read the situation

Two queues approach a reduction where vehicles should combine alternately rather than merge early into one line.

Best response: Continue to the merge point at a controlled speed and alternate with one vehicle from the adjacent queue.

Sign comparison

Don’t confuse it

This sign

Zipper merge ahead

Compare with

Right lane merges left

Key difference

Zipper merge calls for alternating vehicles from two streams at the merge point; the work-zone lane-merge sign only shows which lane ends and where it joins.

Put sign knowledge into practice.

Answer exam-style questions about road signs, traffic lights, and lane markings in clear English.

Mascot holding a blank circular road sign with a red border.