Warning signs · MUTCD W3-4

What does the Be Prepared To Stop sign mean?

The Be Prepared To Stop sign (MUTCD W3-4) is a warning sign under the federal Manual on Uniform Traffic Control Devices, the national standard the states build from. Traffic ahead may be stopped or stopping; slow now.

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

Be Prepared To Stop sign, MUTCD W3-4
Be Prepared To Stop, the federal MUTCD design.

What shape and color is the Be Prepared To Stop sign?

MUTCD codeW3-4
GroupWarning signs
ShapeDiamond
ColorYellow background, black legend 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 Be Prepared To Stop sign often mistaken for?

Signal Ahead (W3-3). W3-4 is also used in work zones and at queues where there is no signal at all.

The Be Prepared To Stop sign compared side by side with the Signal Ahead sign
Be Prepared To Stop sign
Be Prepared To Stopthis sign
Signal Ahead sign
Signal AheadW3-3
GroupWarning signsGroupWarning signs
ShapeDiamondShapeDiamond
ColorYellow background, black legend and borderColorYellow background, black border, signal symbol with red, yellow and green
What it meansTraffic ahead may be stopped or stopping; slow now.What it meansThere is a signal head past the crest or the bend, sited where drivers reach it with little time to react.

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.