Signal Ahead Sign

Updated July 9, 2026

Signal Ahead · MUTCD W3-3 · Warning sign

What the Signal Ahead sign means

This yellow diamond shows a traffic-signal symbol with red, yellow, and green lights, warning that a signalized intersection is coming up. It is posted where the signal may be hard to see in time — after a curve, over a crest, or in fast-moving traffic. Slow down and be prepared to stop if the light is yellow or red. Approaching prepared prevents last-second hard braking or running the light. If the signal is green as you arrive, stay alert in case it changes before you reach it.

What to do when you see it

Ease off the gas and be ready to stop; check the light early so you are not caught by a sudden yellow.

On the CA permit test

Signal Ahead warns of a traffic light you may not see until the last moment — slow and prepare to stop.

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