Stop sign
A red octagon reading STOP. It requires traffic on that approach to come to a full stop before entering the intersection.
How to read it
The octagon belongs to this sign alone: the MUTCD's table of sign shapes reserves it for the stop sign, and Pennsylvania's manual calls it the only octagon-shaped sign on the highway. The stop comes at the painted stop line or crosswalk where there is one, and otherwise before the intersection, as California's and Florida's handbooks describe it. Nothing else is written on its face: the MUTCD does not allow secondary legends on stop signs.
Also searched as: octagon sign, R1-1.
Rules vary by state and country. This explains the sign's standard meaning in the U.S. Manual on Uniform Traffic Control Devices; it isn't legal advice.
Why an octagon
In a 1969 paper for the Highway Research Board, Jose M. Zuniga of the International Road Federation compared the American octagon with the circular stop sign used in parts of Europe. He cited the Road Research Laboratory of England, which found the circular stop sign identified only slightly farther away than the average sign of its system, while the octagon was identified at twice the average distance. The octagon, he pointed out, is not used for any other sign.
Where every approach stops
Where all the roads meeting at an intersection have stop signs, an ALL WAY plaque is mounted below each one.
Read next
- Next in Road signsYield signA red and white triangle pointing down. It gives the right-of-way to traffic on the other road: drivers slow down, and stop only when they need to.
- The same shape in OBD-II trouble codesP0175: System too rich (bank 2)An OBD-II trouble code meaning the fuel system on bank 2 is running with too much fuel for the air.
More road signs
The same shape elsewhere
Browse symbols drawn with letters and numbers.
Sources
- Manual on Uniform Traffic Control Devices for Streets and Highways, 11th edition, MUTCD, U.S. Federal Highway Administration, Section 2B.04, Paragraphs 01, 02, 04 (printed p. 74, PDF p. 114); also Table 2A-1 'Octagon* Stop (R1-1)** […] ** This sign shall be exclusively the shape shown.' (Section 2A.05, printed p. 42)
- Standard Highway Signs and Markings, U.S. Federal Highway Administration, Regulatory Signs, sheet 1-1 (R1-1), PDF p. 1
- MUTCD 2009 Edition, Chapter 2B: Regulatory Signs, Barricades, and Gates, MUTCD 2009, Part 2, U.S. Federal Highway Administration, Section 2B.05
- MUTCD 2009 Edition, Chapter 2A: General, MUTCD 2009, Part 2, U.S. Federal Highway Administration, Section 2A.09, Table 2A-4
- Pennsylvania Driver's Manual, Chapter 2: Signals, Signs and Pavement Markings, Pennsylvania Department of Transportation, p. 10
- California Driver's Handbook, Section 7: Laws and Rules of the Road, California Department of Motor Vehicles, Signs
- Official Florida Driver License Handbook, rev. 08/2023, Florida Department of Highway Safety and Motor Vehicles, p. 47
- The Evolution of MUTCD, Updated December 2023; after H. Gene Hawkins, Jr., ITE Journal, 1991–1994, U.S. Federal Highway Administration, Prologue; Part I
- What Every Driver Must Know, Michigan driver manual, Michigan Department of State, Chapter 5
- International Effort Toward Uniformity on Road Traffic Signs, Signals, and Markings, Jose M. Zuniga, Highway Research Record 299, 1969, Highway Research Board, pp. 1, 4
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 25, 2026. How we research
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