The map above shows the different highway route marker shield designs used by each US state for their own state highways.
While Interstate and US Numbered Highways use standard designs across the country, but the same can not be said of state highway markers.
A few interesting facts:
- Pennsylvania’s design is a keystone, after the state’s nickname.
- Kansas uses a sunflower, which is the state flower.
- Utah uses a beehive since it is known as the beehive state.
- Washington uses a silhouette of George Washington’s bust.
- New Hampshire’s design is based on the Old Man in the Mountain
- New Mexico uses the default circle but adds a Zia sun symbol
- California is the only state not to use a square or rectangle.
- North Dakota’s “Red Tomahawk“ design is slowly being replaced by the state’s outline.
- Colorado design includes their state flag.
- Five states (Delaware, Iowa, Kentucky, Mississippi, and New Jersey) use the default shield
- Alabama, Arizona, Arkansas, Florida, Georgia, Idaho, Louisiana, Missouri, Nevada, Ohio, and Oklahoma all use their state’s outline.
To learn more about the US Highway system have a look at the following books:
- The Big Roads: The Untold Story of the Engineers, Visionaries, and Trailblazers Who Created the American Superhighways
- Divided Highways: Building the Interstate Highways, Transforming American Life
- Interstate 69: The Unfinished History of the Last Great American Highway
- The Last American Highway series
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“Alabama, Arizona, Arkansas, Florida, Georgia, Idaho, Louisiana, Missouri, Nevada, Ohio, and Oklahoma all use their state’s outline.”
This sentences omits South Dakota, which also uses its outline as a shield. Additionally, North Dakota has changed its standards to include its outline.
I know it’s not a primary state highway, but Texas’ FM and RM roads are secondary state highways and Texas is the only state with secondary state highways; I think it’s worthy to put Texas’ FM and RM state shields on this map, perhaps placed side-by-side with the primary state shield (the square).
Several states have secondary highways, with Montana and Tennessee being two examples. Montana’s secondary highways are all signed, and are numbered 201 and up (the primary highways are numbered between 1-200 with a couple exceptions). The Montana secondary highway shield is a downward pointing arrowhead.
Some of Tennessee’s highways are included in both the primary and secondary highway systems; some sections of the same numbered route are considered primary and other segments are considered secondary. Tennessee’s secondary highway shield is a downward pointing triangle with rounded corners.
Nebraska also has secondary roadways as well — Links, Spurs and Recreation Roads (most of the Rec. Roads are no longer signed)… and besides Texas, I’m sure there are a few other states with similar highways.
Missouri has a supplemental route system which is lettered. It uses the standard square without a state name.
New shields in Louisiana are black and white, although numerous green and white shields are still present.
Iowa should change to its state outline. Would be a good fit. Make Iowa yellow on the signs as a nod to the University of Iowa and Iowa State, then use blue numbers as a neutral color.
Surprised Washington doesn’t use a green background, considering the flag is green and it is the Evergreen State.
Arizona can really omit the state name. Most drivers know what Arizona looks like on the map.
FYI, Oklahoma changed from the default to the state outline in 2006.
Vermont started using the green style with the state name on it around the turn of the millennium. There are still a few old signs with the default black-and-white circle. Just when I think they’re all gone I see one in the wild…every time.