Warning signs
Stop Ahead sign
A stop sign is coming that you may not be able to see from a distance.
- Diamond
- Yellow
- MUTCD W3-1
How to recognize it
Shape and background first
ShapeDiamonda diamond stood on its point
BackgroundYellowyellow, the warning color
FamilyWarning signsFederal designation W3-1 in the MUTCD.
Federal designation W3-1 in the MUTCD, the national standard every state signs to.
What the MUTCD specifies
Designation: W3-1
MUTCD Section 2C.35
Conventional road size: 30 x 30 in
Source: Federal Highway Administration, MUTCD 11th Edition (December 2023), Part 2, Table 2C-1; Table 2C-3, Condition B, potential stop, verified 2026-09-26.
Where you will see it
Suggested advance placement distance by posted speed (MUTCD guidance, MUTCD 11th Edition (December 2023), Part 2, Table 2C-1; Table 2C-3, Condition B, potential stop, verified 2026-09-26):
- 35 mph: 250 ft
- 45 mph: 360 ft
- 55 mph: 495 ft
On the test
What the test wants you to know
The mistake people make
The giveaway is the small red octagon inside a yellow diamond. Yellow means warning, so this sign itself never requires you to stop where it stands.
Same family
