Merge Sign

Updated July 9, 2026

Merge · MUTCD W4-1R · Warning sign

What the Merge sign means

This yellow diamond shows two lanes joining into one, warning that traffic will merge from the side ahead — commonly where an on-ramp or an added lane blends into your road. Adjust your speed and spacing to let merging vehicles fit in smoothly, and be ready to move over if it is safe. Merging traffic must yield, but you should cooperate to avoid a conflict. The sign helps prevent side-swipes and rear-end crashes at the merge point by giving both streams of traffic time to adjust.

What to do when you see it

Adjust speed and following distance so merging vehicles can blend in; move over if it is safe.

On the CA permit test

A Merge sign warns that another lane of traffic is about to join yours — adjust speed to let it in.

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