what does this symbol mean?
MUTCD W4-1 A yellow diamond with a curved line joining a straight one

Merge sign

A yellow diamond with a curved line joining a straight one. It warns that traffic from another road or ramp may merge into the lane ahead.

Rules vary by state and country. This explains the sign's standard meaning in the U.S. Manual on Uniform Traffic Control Devices; it isn't legal advice.

How to read it

The MUTCD uses it on the major road ahead of a point where lanes from two roadways come together as a single lane. Pennsylvania's manual adds that entering traffic yields to traffic already on the major road.

Merge or added lane

Where the entering road brings a new lane with it and no merging is needed, the Added Lane sign is used instead.

More road signs

Sources

Last reviewed September 25, 2026 by Rory Hansen. How we research

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