Signal ahead sign
A yellow diamond with a traffic signal. It warns of traffic lights ahead that are not yet in view.
How to read it
The MUTCD requires it on an approach where the signal cannot be seen from far enough away for drivers to respond, judged by a continuous view of at least two signal faces. The view may be blocked by the road's alignment or a structure, or at times by foliage or parked vehicles, and Pennsylvania's manual names a curve or a hill.
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.
Read next
- Next in Road signsMerge signA 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.
- The same shape in BPMN symbolsInclusive gatewayA point where the process takes one or more of several paths, depending on which conditions are true. The inclusive gateway is a diamond with a circle inside.
More road signs
The same shape elsewhere
Browse symbols drawn with circles or diamonds.
Sources
- MUTCD 2009 Edition, Chapter 2C: Warning Signs and Object Markers, MUTCD 2009, Part 2, U.S. Federal Highway Administration, Section 2C.36
- Pennsylvania Driver's Manual, Chapter 2: Signals, Signs and Pavement Markings, Pennsylvania Department of Transportation, p. 16
- Official Florida Driver License Handbook, rev. 08/2023, Florida Department of Highway Safety and Motor Vehicles, p. 50
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 25, 2026. How we research
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