Interstate route sign
A red, white and blue shield with a route number. It marks a road in the Interstate Highway System.
Easily confused with
How to read it
The MUTCD sets its design: a cutout shield with the number in white on blue, the word INTERSTATE in white on red, and a white border, sometimes with the state's name. Interstate numbers are assigned by the American Association of State Highway and Transportation Officials on the states' recommendations.
Also searched as: interstate shield.
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.
Reading the number
The number carries information, as Pennsylvania's manual explains. One- and two-digit even numbers generally run east–west, rising from I-10 in the south to I-94 in the north; odd numbers generally run north–south, rising from I-5 on the West Coast to I-95 on the East. A three-digit number beginning with an even digit usually connects to Interstates at both ends, often as a loop; one beginning with an odd digit is usually a spur, connected at one end.
Read next
- Next in Road signsU.S. route signA white shield with a black route number on a black square. It marks a U.S. numbered highway.
- The same shape in Pottery and porcelain marksLimoges marksLimoges on a mark names a place, the city in central France where porcelain has been made since 1771, not one factory. Many makers have printed it on their wares. Since 2017 the words Porcelaine de Limoges and Limoges are a protected geographical indication, for porcelain made, or made and decorated, in the Haute-Vienne department.
More road signs
The same shape elsewhere
Browse symbols drawn with letters and numbers.
Sources
- MUTCD 2009 Edition, Chapter 2D: Guide Signs for Conventional Roads, MUTCD 2009, Part 2, U.S. Federal Highway Administration, Sections 2D.09, 2D.11
- Pennsylvania Driver's Manual, Chapter 2: Signals, Signs and Pavement Markings, Pennsylvania Department of Transportation, p. 20
- 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, Part I, 1961 Fourth Edition
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 30, 2026. How we research
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