What it looks like
A yellow diamond warning sign with a black symbol showing one lane joining another, indicating traffic merging from the side ahead.
When you'll see it
It appears where an entrance ramp or another lane joins your roadway, common on freeways and major highways.
What to do
Adjust your speed and position to let merging traffic blend in safely, and be ready to change lanes if needed.
Source: Manual on Uniform Traffic Control Devices (MUTCD), 11th Edition — FHWA.
