Editing U.S. Route shield (section)

==Variations==
{{More citations needed section|June 2010|date=June 2010}}
{{imageframe|width=200|content=[[File:US 89 Arizona 1958 North.svg|100px]][[File:US 93 Arizona 1958 South.svg|100px]][[File:US 60 Arizona 1956 West.svg|100px]][[File:US 80 Arizona 1958 East.svg|100px]]|caption=Directional colored U.S. Route shields found in Arizona during the 1950s|align=left}}
[[File:Colored US 17-92.jpg|thumb|upright=0.52|Yellow and blue US&nbsp;17 and US&nbsp;92 shields]]

Several states have experimented with variations on the U.S. Route shield to aid in navigation. Some have used color to denote additional information besides just the route class and number. [[Arizona]] experimented with colors indicating the signed cardinal direction of the highway (orange for north, green for south, brown for east, and blue for west).<ref name="azdot-1964-map">{{cite map |author1 = Arizona Highway Commission |author2 = Rand McNally |author2-link = Rand McNally |year = 1964 |title = Arizona |edition = 1964–65 |scale = c. 1:1,520,640 |location = Chicago |publisher = Rand McNally |url = http://shields.aaroads.com/show.php?image=AZ19610404 |access-date = June 5, 2010 |via = AARoads |oclc = 488796943 }}</ref> [[Florida]], too, used colored signs for its U.S. Highways beginning in 1956, with each highway retaining a single color for its entire length in the state. No two routes using the same color crossed, though an extension of [[U.S. Route 192|US 192]] took it to [[U.S. Route 27|US 27]] (both green). In the 1980s the MUTCD was revised so that these signs were no longer eligible for federal funds.  On August 27, 1993, the decision{{from whom|date=August 2021}} was made to stop producing colored signs.{{cn|date=August 2021}} In California, the design is more like the pre-1961 version. The design has no black background on their U.S. Highway shield. It is instead designed with a white shield with a black outline. Centered on the top are the letters "US". Some states that are part of the [[Appalachian Development Highway System]] feature U.S. Highway signs with blue numbers on a white shield, set against a blue background.

During the era of the 1948 shield, states often modified its design. Several states omitted the letters "U&nbsp;S", leaving only the state name and route number. Other states moved the letters "U&nbsp;S" into the crown of the shield, along with the state name, which was often abbreviated.

[[File:US 13 Business (MD).svg|100px|thumb|right|Marker used for business U.S. Routes in Maryland]]
Many U.S. Highways have loop or spur routes sharing the same number, known as ''[[special route]]s''. These routes typically use the same shield as the mainline route with a "banner" indicating the type of route above the shield. Some states will occasionally indicate the type of the route directly on the shield itself, often in the crown of the shield. [[Maryland]] uses green shields with the word "BUSINESS" in the shield's crown for U.S. [[business route]]s, reflecting a similar practice used nationwide for business Interstate shields.

On some Business U.S. Routes in Illinois, mostly on Business US&nbsp;51 in the Bloomington–Normal area, the standard black on white US Route shield is used but the abbreviation "BUSN" is included in smaller letters at the top of the shield.<ref>{{cite web |author = ((Google)) |author-link = Google |date = January 2016 |title = Bus. US&nbsp;51 Northbound |url = https://www.google.com/maps/@40.4398628,-88.9908547,3a,37.5y,7.34h,81.54t/data=!3m7!1e1!3m5!1s19eOs2YrvsjGtMfXDDs2XA!2e0!6s%2F%2Fgeo1.ggpht.com%2Fcbk%3Fpanoid%3D19eOs2YrvsjGtMfXDDs2XA%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D269.92957%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656 |work = [[Google Street View]] |access-date = October 2, 2017}}</ref> This is also the case for the markers used on signs on nearby Interstates.<ref>{{cite web |author = ((Google)) |date = September 2016 |title = I-74 at Exit 135 |url = https://www.google.com/maps/@40.4361026,-88.9862468,3a,75y,284.24h,90t/data=!3m6!1e1!3m4!1sglQqrdZm67RV4BuSHAZ6yw!2e0!7i13312!8i6656 |work = Google Street View |access-date = October 2, 2017 }}</ref>