Regulatory signs
No U Turn sign
You may not make a complete turn to travel in the opposite direction at this location.
- Square
- White
- MUTCD R3-4
How to recognize it
Shape and background first
ShapeSquarea square
BackgroundWhitewhite, the standard background for a rule you must obey
FamilyRegulatory signsFederal designation R3-4 in the MUTCD.
Federal designation R3-4 in the MUTCD, the national standard every state signs to.
What the MUTCD specifies
Designation: R3-4
MUTCD Section 2B.26
Conventional road size: 24 x 24 in
Standard: Install a movement prohibition sign where U-turns are prohibited on an intersection approach, subject to the section's exceptions.
Source: Federal Highway Administration, MUTCD 11th Edition (December 2023), Part 2, Table 2B-1; Section 2B.26, verified 2026-09-26.
On the test
What the test wants you to know
The mistake people make
A red circle with a diagonal slash always means the pictured action is prohibited. Where no sign is posted, U turns are generally legal unless your state bans them at signals or on curves, so read the question carefully.
