Warning signs · MUTCD W1-11

What does the Hairpin Curve sign mean?

The Hairpin Curve sign (MUTCD W1-11) is a warning sign under the federal Manual on Uniform Traffic Control Devices, the national standard the states build from. The road doubles back on itself at very low speed.

Source: MUTCD 11th Edition, Chapter 2C, Table 2C-1, checked 2026-09-09.

Hairpin Curve sign, MUTCD W1-11
Hairpin Curve, the federal MUTCD design.

What shape and color is the Hairpin Curve sign?

MUTCD codeW1-11
GroupWarning signs
ShapeDiamond
ColorYellow background, black symbol and border

What a diamond means. A warning. It tells you what the road does next and obliges you to do nothing in particular, which is the distinction test writers probe most often.

What yellow means. General warning of a permanent condition ahead.

Warning signs. A diamond reports a condition and orders nothing. What you do about it is left to you, and that gap between a report and an order is what test writers keep probing.

What is the Hairpin Curve sign often mistaken for?

270-degree Curve (W1-15), used on loop ramps, and the ordinary Turn sign (W1-1).

The Hairpin Curve sign compared side by side with the Turn sign
Hairpin Curve sign
Hairpin Curvethis sign
Turn sign
TurnW1-1
GroupWarning signsGroupWarning signs
ShapeDiamondShapeDiamond
ColorYellow background, black symbol and borderColorYellow background, black symbol and border
What it meansThe road doubles back on itself at very low speed.What it meansThe alignment breaks sharply, close to a right angle.

What are the other warning signs?

All 55 warning signs on one page, or every US road sign by shape and color.

Test yourself on this sign and the rest of the set with a road signs practice test for Florida, Texas or California.

The artwork is the federal design itself, which the manual dedicates to the public domain in MUTCD 11th Edition, Part 1, Section 1D.06, checked 2026-09-09. The Interstate Shield, the 511 pictograph and the National Scenic Byway graphic are named exceptions and are not reproduced anywhere on this site.

Source: Manual on Uniform Traffic Control Devices, 11th Edition. Not affiliated with or endorsed by the Federal Highway Administration or any state agency.