No U-turn sign: what it means
The No U-turn sign means you must not make a U-turn at that location. The red circle and slash show the move is prohibited.
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What it means
MUTCD Section 2B.26 calls it a Movement Prohibition sign. These signs go where a particular turn or movement is banned at an intersection. A No U-turn sign should be placed where a No Left Turn sign would go, such as over the road or on the far left corner.
If both left turns and U-turns are banned, a combined No U or Left Turn sign should be used instead.
Where you see it
At intersections and median openings where turning around is not allowed.
A common mistake
Thinking it does not matter on an empty road. The ban applies whatever the traffic; keep going to a place where turning around is legal.
Quick quiz
What does the No U-turn sign prohibit?
- Turning around to go back the way you came
- Turning right
- Changing lanes
Show answer
A. Turning around to go back the way you came. The R3-4 sign prohibits U-turns at that intersection approach. Source: MUTCD 11th Edition, Chapter 2B, Regulatory Signs, Barricades, and Gates: Section 2B.26, FHWA; MUTCD 11th Edition, FHWA
Compare with
No turn on red signWait for the green before turning.
One way signAll traffic moves in the arrow’s direction.
Do not enter signTraffic comes toward you here; do not go in.
Next in regulatory signs: No turn on red sign. See all regulatory signs or the full road signs list.
Want to test someone else? Play a road-sign quiz with friends and family.
Sources
- MUTCD 11th Edition, Chapter 2B, Regulatory Signs, Barricades, and Gates: Section 2B.26, FHWA
- MUTCD 11th Edition, FHWA. FHWA lists the current version as the 11th Edition with Revision 1, dated December 2025
Sign pictures are our own simplified drawings of the MUTCD designs, which are in the public domain (MUTCD Section 1D.06). Sources and image credits.