What does the Reduced Speed Limit Ahead sign mean?
The Reduced Speed Limit Ahead sign (MUTCD W3-5) is a warning sign under the federal Manual on Uniform Traffic Control Devices, the national standard the states build from. A lower speed limit begins shortly; start slowing so you are legal when you reach it.
Source: MUTCD 11th Edition, Chapter 2C, Table 2C-1, checked 2026-09-09.
What shape and color is the Reduced Speed Limit Ahead sign?
| MUTCD code | W3-5 |
|---|---|
| Group | Warning signs |
| Shape | Diamond |
| Color | Yellow 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 Reduced Speed Limit Ahead sign often mistaken for?
The Speed Limit sign (R2-1) itself. The reduced limit is not in force where W3-5 stands.
|  |
|---|---|
| GroupWarning signs | GroupRegulatory signs |
| ShapeDiamond | ShapeVertical rectangle |
| ColorYellow background, black legend and border | ColorWhite background, black legend and border |
| What it meansA lower speed limit begins shortly; start slowing so you are legal when you reach it. | What it meansA ceiling fixed by law, and it assumes the best case: dry pavement, clear sight lines, light traffic. |
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.