A supplemental route is a state secondary road in the
U.S. state of
Missouri
Missouri is a state in the Midwestern region of the United States. Ranking 21st in land area, it is bordered by eight states (tied for the most with Tennessee): Iowa to the north, Illinois, Kentucky and Tennessee to the east, Arkansas t ...
, designated with letters. Supplemental routes were various roads within the state which the
Missouri Department of Transportation
The Missouri Department of Transportation (MoDOT, ) is a state government organization in charge of maintaining public roadways of the U.S. state of Missouri under the guidance of the Missouri Highways and Transportation Commission. MoDOT designs ...
was given in 1952 to maintain in addition to the regular routes,
though lettered routes had been in use from at least 1932. The four types of roads designated as Routes are:
* Farm to market roads
* Roads to
state park
State parks are parks or other protected areas managed at the sub-national level within those nations which use "state" as a political subdivision. State parks are typically established by a state to preserve a location on account of its natural ...
s
* Former alignments of
U.S. or state highways
* Short routes connecting state highways from other states to routes in Missouri
Supplemental routes make up (59%) of the state highway system.
History
Prior to 1907, all road improvement activities in Missouri were undertaken by the individual counties, with little expertise or coordination between them. Amid growing automobile presence and insufficient road networks in Missouri in the ensuing years, the state legislature created a state highway department and the state highway commission as well as enacted various laws aimed at improving transportation in the state.
In 1920, recognizing that economic prosperity and growth are highly related to good transportation, the legislature passed a $60 million bond issue for road work.
This effort, along with the Centennial Road Law passed by the legislature in 1921, shifted highway building efforts in Missouri from the local level to the state level. As a result, the state highway commission undertook an aggressive road building campaign throughout the 1920s and 1930s aimed to get Missouri "out of the mud".
In 1952, the state highway department embarked on its Missouri 10-Year Highway Modernization and Expansion Program. Through this effort, the state assumed maintenance responsibility of over an additional of secondary and farm-to-market roads previously managed by the counties.
The goal of the secondary highway system was to place state-maintained roads within of more than 95% of all rural farm houses, schools, churches, cemeteries and stores.
Most of Missouri's lettered supplemental highways are the result of this program.
Highway designations
The more major supplemental routes of the system are assigned single-letter designations (such as "K"). Minor branch routes and farm-to-market roads, which often end at county roads or are former alignments of the other highways, are typically assigned two-letter designations consisting of two of the same letter (e.g. "KK"). Additionally, combinations of letters may be used, but always with A as the first letter (such as "AD"); the only exceptions to this are Route BA in western
St. Louis County and Route RA in
Lee's Summit, Missouri
Lee's Summit is a city located within the counties of Jackson (primarily) and Cass in the U.S. state of Missouri. It is a suburb of Kansas City, Missouri. As of the 2020 census its population was 101,108, making it the sixth-largest city in bo ...
. Combinations beginning with the letter R are also used for routes that connect with state parks or other recreational facilities, which is the only use of R on the system; Route AR, a non-recreational route south of
Bakersfield
Bakersfield is a city in Kern County, California, United States. It is the county seat and largest city of Kern County. The city covers about near the southern end of the San Joaquin Valley and the Central Valley region. Bakersfield's pop ...
, is the only exception to this.
The vast majority of the highways in the system are designated with 19 letters of the alphabet. The letters "G", "I", "L", "Q", and "S" are not used because of the potential confusion with other letters and numbers. The only current use of X is on Route AX in Macon County.
Supplemental routes rarely run for more than a few miles, although they may cross county lines. A route's designation changes at a
U.S. Route
The United States Numbered Highway System (often called U.S. Routes or U.S. Highways) is an integrated network of roads and highways numbered within a nationwide grid in the contiguous United States. As the designation and numbering of these hi ...
or
Interstate highway
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, is a network of controlled-access highways that forms part of the National Highway System in the United States. T ...
; for example, in
Greene County, southbound Route J crosses
U.S. Route 60 and becomes Route NN, and Route M in
Cole County becomes Route J after passing
U.S. Route 50. However, when Route MM in Greene County crosses
Route 360, it remains Route MM, only changing to Route B when crossing
Interstate 44
Interstate 44 (I-44) is a major Interstate Highway in the central United States. Although it is nominally an east–west road as it is even-numbered, it follows a more southwest–northeast alignment. Its western terminus is in Wichita Fal ...
. Route J in Boone County is one of the few exceptions to this, as it continues past
U.S. 40
U.S. Route 40 or U.S. Highway 40 (US 40), also known as the Main Street of America, is a major east–west United States Highway traveling across the United States from the Mountain States to the Mid-Atlantic States. As with most routes ...
for three miles before becoming Route O upon passing
I-70
Interstate 70 (I-70) is a major east–west Interstate Highway in the United States that runs from I-15 near Cove Fort, Utah, to a park and ride lot just east of I-695 in Baltimore, Maryland, and is the fifth-longest Interstate in the c ...
. Designations are also reused, but not near one another. For example, Route D exists in the counties of Cole, Greene, Newton, St. Louis, and several others. Rarely is a designation reused in a county; exceptions include two highways designated Route Z in
Randolph County and two highways designated Route K in
Carter County.
In some cases, supplemental routes will share a
concurrency with a state route or another supplemental route. For example, Route J in
Howard County overlaps with
Route 87 for about near
Boonesboro, Route D in Greene County overlaps with
Route 125 for a few miles, Route N and Route O in
Franklin County overlap for between Catawissa and Robertsville, and Route CC in
Moniteau County overlaps with Route C for a few miles.
Signage
Supplemental routes are signed by black letters on a white background with a black border. Rarely, the shields will be marked with banners such as EAST, WEST, or END. There are no business or bypass routes for the roads; however, seven examples exist of
spur route
A spur route is a short road forming a branch from a longer, more important road such as a freeway, Interstate Highway, or motorway. A bypass or beltway should not be considered a true spur route as it typically reconnects with another or the ...
s: Spur Route N in
Cedar County
Cedar County may refer to:
* Cedar County, Iowa
* Cedar County, Missouri
* Cedar County, Nebraska
* Cedar County, Choctaw Nation
* Cedar County, Washington, a proposed county made up of part of King County
* Cedar County, Utah Territory, a forme ...
, Spur Route C in
Gentry County, Spur Route C (to
Union Covered Bridge State Historic Site
The Union Covered Bridge State Historic Site is a Missouri State Historic Site in Monroe County, Missouri. The covered bridge is a Burr-arch truss structure built in 1871 over the Elk Fork of the Salt River. It was almost lost to neglect i ...
) in
Monroe County Monroe County may refer to seventeen counties in the United States, all named for James Monroe:
* Monroe County, Alabama
*Monroe County, Arkansas
* Monroe County, Florida
* Monroe County, Georgia
*Monroe County, Illinois
*Monroe County, Indian ...
, Spur Route K (into East Lynn) in
Cass County, Spur Route AA (to the
Sappington Cemetery State Historic Site
Sappington Cemetery State Historic Site is a Missouri state historic site located approximately southwest of Arrow Rock in Saline County. The cemetery houses the graves of John Sappington and two of his sons-in-law, Meredith Miles Marmaduke an ...
) in
Saline County, Spur Route J (to
Sigsbee) in Shelby County, Spur Route V in
Butler County, and Spur Route Y in
Montgomery County. Then, one connector route: Connector
Route M in
Jefferson County
It is erroneously believed that due to these roads being designated by letters rather than numbers and their existing in more than one county that these roads are county roads, not state highways, with some businesses and residences located on these roads saying their address is "County Road A" for example. This may have also arisen from the signage used prior to the early 1960s, where the letter was painted black against a white background, with the words "STATE ROAD" above the letter and the county name (in all capital letters) below the letter, or from the use of letters representing
county trunk routes in Wisconsin.
See also
*
Missouri Route M (Jefferson County)
*
Special route
In road transportation in the United States, a special route is a road in a numbered highway system that diverts a specific segment of related traffic away from another road. They are featured in many highway systems; most are found in the Int ...
References
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Supplemental