Missouri State Highway System
 | This article includes a list of references, related reading, or external links, but its sources remain unclear because it lacks inline citations. (October 2018) |
| Missouri State Highway System | |
|---|---|
   Highway markers for Interstate 70, U.S. Route 65, Missouri Route 7 Supplement Route A and Supplement Route JJ | |
| System information | |
| Maintained by MoDOT | |
| Highway names | |
| Interstates | Interstate nn (I‑nn) |
| US Highways | U.S. Route nn (US nn) |
| State | Route nn |
| Supplemental Route: | Supp-xx, SSR-xx |
| System links | |
In Missouri, odd-numbered highways run north-south and even-numbered highways run east-west (with a few exceptions, such as Route 112). Missouri also maintains a secondary set of roads, supplemental routes, which are lettered rather than numbered.
Missouri has also changed highway designations with a US route or an interstate with the same number is designated through the state (Route 40 was redesignated Route 14 to avoid duplicating numbers with US-40 which also passes through the state). There are a few instances of number duplication between federal and state highways (such as with Route 72 and I-72), but any such pairs of highways are nowhere near each other to avoid confusion.
In some states (such as Arkansas and New Mexico), highways are allowed to be discontinuous. Missouri overlaps highways in order to maintain continuity.
The Missouri Department of Transportation routinely uses the term "Route" in reference to the names of the roads. However, Missouri statutes define them as "State Highways". Missourians may use the terms "Route" and "Highway" interchangeably when referring to a state road.
Interstates in Missouri
Primary
Secondary
Business Loops
U.S. Highways in Missouri
Primary
Secondary
State Highways in Missouri
Primary
State Highways of 100 - 200 miles
State Highways of at least 200 miles
Other popular state routes
Secondary
Popular state routes
Specially designated state routes
- 
| Number | Length (mi)off | Length (km) | Southern or western terminus | Northern or eastern terminus | Formed | Removed | Notes | |
|---|---|---|---|---|---|---|---|---|
  Route 27
|
— | — | — | — | — | — | Avenue of the Saints | |
   Route 110 (CKC)
|
— | — | — | — | — | — | Chicago–Kansas City Expressway | |
Supplemental routes
Primary
Route Examples
Missouri does not use letters "G", "I", "L", "Q", and "S" because of the potential confusion with other letters and numbers. The letter "R" is reserved for access to state parks. The letter "X" is only used as an exception. Each county in Missouri may have its own letter route system. Therefore, there a several separate routes with the same letters through out the state.
Secondary
Route Examples
Most secondary supplemental routes are assigned with two-letter designations consisting of two of the same letter (e.g. "KK"). However, combinations of letters may be used. Combinations beginning with the letter R are also used for routes that connect with state parks or other recreational facilities. Routes "GG", "II", "LL", "QQ", "RR", "SS", "VV", "WW", and "XX" are not used to avoid confusion with other letters, numbers and signage.
Exception Examples
See also
References
External links
- Missouri Department of Transportation website
- Official MoDOT Travel Information Map
- Official current and historical Missouri road maps
- Kansas City Scout - KC area intelligent transportation system
- St. Louis Metro area intelligent transportation program website
- Road Signs of Missouri
- Missouri Highways (unofficial)