Numbered highways in the United States

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Highways in the United States are split into at least four different types of systems: Interstate Highways, U.S. Highways, state highways, and county highways. Highways are generally organized by a route number or letter. These designations are generally displayed along the route by means of a highway shield. Each system has its own unique shield design that will allow quick identification to which system the route belongs. Below is a list of the different highway shields used throughout the United States.

Highway A public road or other public way on land

A highway is any public or private road or other public way on land. It is used for major roads, but also includes other public roads and public tracks: It is not an equivalent term to controlled-access highway, or a translation for autobahn, autoroute, etc.

A routenumber is an identifying numeric designation assigned by a highway authority to a particular stretch of roadway to distinguish it from other routes and, in many cases, also to indicate its classification, general geographical location and/or orientation. The numbers chosen may be used solely for internal administrative purposes; however, in most cases they are also displayed on roadside signage and indicated on maps.

Highway shield sign denoting the route number of a highway

A highway shield or route marker is a sign denoting the route number of a highway, usually in the form of a symbolic shape with the route number enclosed. As the focus of the sign, the route number is usually the sign's largest element, with other items on the sign rendered in smaller sizes or contrasting colors. Highway shields are used by travellers, commuters, and all levels of government for identifying, navigating, and organising routes within a county, state, province, or country. Simplified highway shields often appear on maps.


Interstate Highways

Interstate Highway shields
Standard Interstate
Standard Interstate, wide
I-80 (IA).svg
California- and Iowa-style Interstate
Business Loop 19.svg
Business Loop
Business Spur 44.svg
Business Spur

The Interstate Highway System is a federally funded and administered (but state-maintained) system of freeways that forms the transportation backbone of the U.S., with millions of Americans relying on it for commutes, long-distance travel, and freight transport daily. Interstate highways are all constructed to precise standards, designed to maximize high-speed travel safety and efficiency. Interstate Highways also contain auxiliary routes, which are normally assigned a three-digit route number. All Interstate Highways are part of the National Highway System, a network of highways deemed essential to the defense, economy, and mobility of the country.

Standards for Interstate Highways in the United States are defined by the American Association of State Highway and Transportation Officials (AASHTO) in the publication A Policy on Design Standards: Interstate System. For a certain highway to be considered an Interstate Highway, it must meet these construction requirements or obtain a waiver from the Federal Highway Administration.

National Highway System (United States) highway system in the United States

The National Highway System (NHS) is a network of strategic highways within the United States, including the Interstate Highway System and other roads serving major airports, ports, rail or truck terminals, railway stations, pipeline terminals and other strategic transport facilities. Altogether, it constitutes the largest highway system in the world.

U.S. Highways

U.S. Highway shields
US 20.svg
Standard U.S. Highway
US 287.svg
Standard U.S. Highway, wide
US 6 (CA).svg
California-style U.S. Highway
US 61 (1961).svg
1961-era U.S. Highway
US 27 Michigan 1948.svg
1948-era U.S. Highway
US 66 Arizona 1926.svg
1926-era U.S. Highway

The United States Numbered Highway System is an older system consisting mostly of surface-level trunk roads, coordinated by the American Association of State Highway and Transportation Officials and maintained by state and local governments. U.S. Highways have been relegated to regional and intrastate traffic, as they have been largely supplanted by the Interstate system for long-distance travel except in areas (especially in the west) where the Interstate system is absent or underdeveloped. This has led to the decommissioning and truncation of U.S. Highways that were formerly vital long-haul routes, such as U.S. Route 21 and U.S. Route 66.

The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test protocols and guidelines which are used in highway design and construction throughout the United States. Despite its name, the association represents not only highways but air, rail, water, and public transportation as well.

U.S. Route 21 highway in the United States

U.S. Route 21 or U.S. Highway 21 (US 21) is a north–south United States Numbered Highway in the Southeastern United States that travels 394 miles (634 km). The southern terminus is in Hunting Island State Park, South Carolina, 14.4 miles (23.2 km) of US 21 Business and South Carolina Highway 802 (SC 802) in Beaufort. The northern terminus is in Wytheville, Virginia at an interchange with Interstate 81 (I-81) and US 52. It travels through the states of South Carolina, North Carolina, and Virginia. It also connects through major Southeastern cities such as Columbia, South Carolina and Charlotte, North Carolina. The northern portion of the road travels parallel to I-77 in northern South Carolina and North Carolina. The road also has three interchanges with I-26 in Lexington and Calhoun counties in South Carolina.

U.S. Route 66 Former US Highway between Chicago and Los Angeles

U.S. Route 66, also known as the Will Rogers Highway, the Main Street of America or the Mother Road, was one of the original highways in the U.S. Highway System. US 66 was established on November 11, 1926, with road signs erected the following year. The highway, which became one of the most famous roads in the United States, originally ran from Chicago, Illinois, through Missouri, Kansas, Oklahoma, Texas, New Mexico, and Arizona before ending in Santa Monica in Los Angeles County, California, covering a total of 2,448 miles (3,940 km). It was recognized in popular culture by both the hit song "(Get Your Kicks on) Route 66" and the Route 66 television show in the 1960s. In John Steinbeck's classic American novel, The Grapes of Wrath (1939), the road, "Highway 66", was turned into a powerful symbol of escape and loss.

State highways

State highway shields

Each state also has a state highway system. State highways are of varying standards, capacity, and quality. Some state highways become so heavily traveled they are built to Interstate Highway standards. Others are more lightly traveled and have low capacity.

Many state highway markers are designed to suggest the geographic shape of the state or some other state symbol such as its flag. Most of the others are generically rectangular or some other neutral shape. The default design for state highway markers is the circular highway shield, which is how state highways are designated on most maps and atlases. Currently, five states—Delaware, Iowa, Kentucky, Mississippi, and New Jersey—use the circular shield for road signage on their state highways. [1]

Delaware State of the United States of America

Delaware is one of the 50 states of the United States, in the South-Atlantic or Southern region. It is bordered to the south and west by Maryland, north by Pennsylvania, and east by New Jersey and the Atlantic Ocean. The state takes its name from Thomas West, 3rd Baron De La Warr, an English nobleman and Virginia's first colonial governor.

Iowa State of the United States of America

Iowa is a state in the Midwestern United States, bordered by the Mississippi River to the east and the Missouri River and Big Sioux River to the west. It is bordered by six states; Wisconsin to the northeast, Illinois to the east, Missouri to the south, Nebraska to the west, South Dakota to the northwest and Minnesota to the north.

Kentucky State of the United States of America

Kentucky, officially the Commonwealth of Kentucky, is a state located in the east south-central region of the United States. Although styled as the "State of Kentucky" in the law creating it, (because in Kentucky's first constitution, the name state was used) Kentucky is one of four U.S. states constituted as a commonwealth. Originally a part of Virginia, in 1792 Kentucky became the 15th state to join the Union. Kentucky is the 37th most extensive and the 26th most populous of the 50 United States.

Federal district and territory highways

Federal district and territory highway shields
PR primary 1.svg
Puerto Rico Primary

There are also numbered highways in the District of Columbia and the five territories. Likewise, they may also vary in standards and quality.

Territories of the United States political division that is directly overseen by the United States Federal Government

Territories of the United States are sub-national administrative divisions overseen by the federal government. They differ from U.S. states and Native American tribes, which have limited sovereignty. The territories are classified by incorporation and whether they have an "organized" government through an organic act passed by Congress.

Secondary highways

Secondary state highway shields
Arizona 101.svg
Arizona Loop
Missouri Supp.
Montana Sec.
N LINK 25A.svg
Neb. Link
N REC 82B.svg
Neb.Rec. Road
N SPUR 78D.svg
Neb. Spur
PA QR 3032.svg
Penn. Quadrant Route
Secondary Tennessee 14.svg
Texas Beltway 8.svg
Texas Beltway
Texas FM 1960.svg
Texas FM Road
Texas Loop 1604.svg
Texas Loop
Texas NASA Road 1.svg
Texas NASA Road
Texas Park Road 33.svg
Texas Park Road
Texas RM 2243.svg
Texas RM Road
Texas Recreational Road 255.svg
Texas Rec. Road
Texas Spur 366.svg
Texas Spur
Circle sign 35.svg
Vermont Town Highway
Circle sign 620.svg
Virginia Sec.

Some states may include a secondary highway system to supplement the main one, usually for a specific purpose. For example, Texas established a system of farm-to-market roads to specifically improve access to rural areas. Nebraska has Connecting Link, Spur, and Recreation Highways to provide access to small towns and state parks. The Missouri supplemental route system was designed to provide access to most farm houses, schools, churches, cemeteries, and stores within the state.

Farm-to-market road type of road

In the United States, a farm-to-market road or ranch-to-market road is a state road or county road that connects rural or agricultural areas to market towns. These are better quality roads, usually a highway, that farmers and ranchers use to transport products to market towns or distribution centers.

A supplemental route is a state secondary road in the U.S. state of Missouri, designated with letters. Supplemental routes were various roads within the state which the Missouri Department of Transportation was given in 1952 to maintain in addition to the regular routes, though lettered routes had been in use from at least 1932. The goal of the secondary highway system was to place state-maintained roads within 2 miles (3 km) of more than 95% of all farm houses, schools, churches, cemeteries and stores. The four types of roads designated as Routes are:

County highways

County highway shields
Baldwin County Route 64 AL.svg
Standard County
St Louis County Route 7 MN.svg
Square variant
Clark County Route 215 NV.svg
Clark County, Nev., variant
Circle sign 9-1.svg
West Virginia variant
WIS County Z.svg
Wisc. variant
Scioto County Route 28 OH.svg
Scioto County, Ohio, variant

The final administrative level in some states is the county highway. As the name suggests, this type of road is maintained by a county. County roads vary widely from well-traveled multilane highways to dirt roads into remote parts of the county. In Louisiana, parish roads exist in place of county highways, as counties in that state are called parishes. Alaska also has no counties, and all roads are maintained at the national, state or municipal level. In some states, such as Massachusetts, county roads are now administered by regional entities. [2]

Other systems

Other systems
Forest Route 16.svg
Forest Highway
Indian Route 18.svg
Indian Route
US Bike 1 (M1-9).svg
Bicycle Route
Harmony Township Route 92, Morrow County, Ohio.svg
Standard Ohio Township Route sign, Harmony Township Route 92
Charlotte Route 4 shield.svg
Charlotte, NC, City Route
Rochester Inner Loop.svg
Inner Loop, Rochester, NY

Other highway systems include:


In 1918, Wisconsin became the first state to number its highways in the field. [3] In 1926 the American Association of State Highway Officials (AASHO) established and numbered interstate routes (United States Numbered Highways), selecting the best roads in each state that could be connected to provide a rational network of federal highways. [4]

See also

Related Research Articles

Interstate Highway System United States highway system

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. The system is named for President Dwight D. Eisenhower, who championed its formation. Construction was authorized by the Federal Aid Highway Act of 1956, and the original portion was completed 35 years later, although some urban routes were cancelled and never built. The network has since been extended. In 2016, it had a total length of 48,181 miles (77,540 km). As of 2016, about one-quarter of all vehicle miles driven in the country use the Interstate system. In 2006, the cost of construction was estimated at about $425 billion.

United States Numbered Highway System highway system of the United States of America

The United States Numbered Highway System 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 highways were coordinated among the states, they are sometimes called Federal Highways, but the roadways were built and have always been maintained by state or local governments since their initial designation in 1926.

A state highway, state road, or state route is usually a road that is either numbered or maintained by a sub-national state or province. A road numbered by a state or province falls below numbered national highways in the hierarchy. Roads maintained by a state or province include both nationally numbered highways and un-numbered state highways. Depending on the state, "state highway" may be used for one meaning and "state road" or "state route" for the other.

Highways in Australia describes the highways of Australia

Highways in Australia are generally high capacity roads managed by state and territory government agencies, though Australia's federal government contributes funding for important links between capital cities and major regional centres. Prior to European settlement, the earliest needs for trade and travel were met by narrow bush tracks, used by tribes of Indigenous Australians. The formal construction of roads began in 1788, after the founding of the colony of New South Wales, and a network of three major roads across the colony emerged by the 1820s. Similar road networks were established in the other colonies of Australia. Road construction programs in the early 19th century were generally underfunded, as they were dependent on government budgets, loans, and tolls; while there was a huge increase in road usage, due to the Australian gold rushes. Local government authorities, often known as Road Boards, were therefore established to be primarily responsible for funding and undertaking road construction and maintenance. The early 1900s saw both the increasingly widespread use of motorised transportation, and the creation of state road authorities in each state, between 1913 and 1926. These authorities managed each state's road network, with the main arterial roads controlled and maintained by the state, and other roads remaining the responsibility of local governments. The federal government became involved in road funding in the 1920s, distributing funding to the states. The depression of the 1930s slowed the funding and development of the major road network until the onset on World War II. Supply roads leading to the north of the country were considered vital, resulting in the construction of Barkly, Stuart, and Eyre Highways.

The U.S. Route shield is the highway marker used for United States Numbered Highways. Since the first U.S. Route signs were installed in 1926, the general idea has remained the same, but many changes have been made in the details. Originally, the shield included the name of the state in which the sign was erected and the letters "U S" on a shield-shaped sign. Over time, the shield has been simplified to consist of a white shield outline on a black square background, containing only a black route number. However, because each state is responsible for the production and maintenance of U.S. Route shields, several variants of the shield have existed over the years.

Business route short special route connected to a parent numbered highway at its beginning, then routed through the central business district of a nearby city or town, and finally reconnecting with the same parent numbered highway again at its end

A business route in the United States is a short special route connected to a parent numbered highway at its beginning, then routed through the central business district of a nearby city or town, and finally reconnecting with the same parent numbered highway again at its end.

County highway type of highway

A county highway is a road in the United States and in the Canadian province of Ontario that is designated and/or maintained by the county highway department. Route numbering can be determined by each county alone, by mutual agreement among counties, or by a statewide pattern.

A reassurance marker or confirming marker is a type of traffic sign that confirms the identity of the route being traveled without providing information found on other types of road signs, such as distances traveled as is done by highway location markers, distances to other locations or upcoming intersections.

In the state of Maine, the Maine Department of Transportation (MaineDOT) has a system of numbered highways, defined as the "connected main highways throughout the state which primarily serve arterial or through traffic." As of 2006, 22,236 miles of roadway are included in the highway system, including Interstate highways, U.S. Routes, state highways, and other urban and rural local roads.

Transportation in California

California's transportation system is complex and dynamic. Although known for its car culture and extensive network of freeways and roads, the state also has a vast array of rail, sea, and air transport. Several subway, light rail, and commuter rail networks are found in many of the state's largest population centers. In addition, with the state's location on the West Coast of the United States, several important ports in California handle freight shipments from the Pacific Rim and beyond. A number of airports are also spread out across the state, ranging from small general aviation airports to large international hubs like Los Angeles International Airport and San Francisco International Airport.

Nebraska State Highway System highway system

The Nebraska State Highway System consists of all the state highways in Nebraska maintained by the Nebraska Department of Roads. This includes federally designated Interstates and US Highways as well as state highways, links and spurs. The system comprises 9,942 miles (16,000 km) of state highways in all 93 counties. Highways within the system range in scale and quality from 10-lane urban freeways, such as I-80 around Omaha, to standard two-lane rural undivided highways as well as 39 miles (63 km) of state highways that remain unpaved such as N-67 north of Dunbar. Surrounding landscapes along the highway system range from the urban areas in Omaha and Lincoln to scenic journeys through uninhabited grasslands in the Nebraska Sandhills.

Numbered highways in New York highway system

The New York State Department of Transportation (NYSDOT) is responsible for the establishment and classification of a state highway network which includes Interstate Highways, U.S. Highways, and state routes. U.S. and Interstate Highways are classified as state routes in New York; however, a letter is suffixed to the number of the route. As a result, there is apparent duplication between U.S. Routes, Interstate Highways and state routes.

An unsigned highway is a highway that has been assigned a route number, but does not bear road markings that would conventionally be used to identify the route with that number. Highways are left unsigned for a variety of reasons, and examples are found throughout the world. Depending on the policy of the agency that maintains the highway, and the reason for not signing the route, the route may instead be signed a different designation from its actual number, with small inventory markers for internal use, or with nothing at all.

In the U.S. state of Pennsylvania, state highways are maintained by the Pennsylvania Department of Transportation. Each is assigned a four-digit State Route (SR) number in the present Location Referencing System. Traffic Routes are signed as Interstate Highways, U.S. Routes and Pennsylvania Routes, and are prefixed with one to three zeroes to give a four-digit number. PA Routes are also called Pennsylvania Traffic Routes, and formerly State Highway Routes.

Road signs in the United States Road signs in the United States

In the United States, road signs are, for the most part, standardized by federal regulations, most notably in the Manual on Uniform Traffic Control Devices (MUTCD) and its companion volume the Standard Highway Signs (SHS). There are no plans for adopting the Vienna Convention on Road Signs and Signals standards.

Iowa Primary Highway System highway system

The primary highway system makes up over 9,000 miles (14,000 km), a mere 8 percent of the U.S. state of Iowa's public road system. The Iowa Department of Transportation is responsible for the day-to-day maintenance of the primary highway system, which consists of Interstate Highways, United States Highways, and Iowa state highways. Currently, the longest primary highway is U.S. Route 30 at 332 miles (534 km). The shortest highway is Interstate 129 at 0.27 miles (0.43 km).

Glossary of road transport terms Wikimedia list article

Terminology related to road transport—the transport of passengers or goods on paved routes between places—is diverse, with variation between dialects of English. There may also be regional differences within a single country, and some terms differ based on the side of the road traffic drives on. This glossary is an alphabetical listing of road transport terms.

Delaware State Route System highway system

The Delaware State Route System consists of roads in the U.S. state of Delaware that are maintained by the Delaware Department of Transportation (DelDOT). The system includes the portions of the Interstate Highway System and United States Numbered Highways system located in the state along with state routes and other roads maintained by DelDOT. All roads maintained by the state are assigned a maintenance road number that is only marked on little white markers at intersections and on auxiliary plates below warning signs approaching intersections. These numbers are only unique in a specific county, some roads can be designated with multiple road numbers, and numbers do not necessarily correspond to the signed Interstate, U.S., or state route numbers. DelDOT maintains a total of 5,386.14 miles (8,668.15 km) of roads, comprising 89 percent of the roads within the state. Some large bridges in the state are maintained by other agencies including the U.S. Army Corps of Engineers and the Delaware River and Bay Authority. Roads in the system include multilane freeways, multilane surface divided highways, and two-lane undivided roads serving urban, suburban, and rural areas. Some of the roads maintained by DelDOT are toll roads, in which motorists must pay to use.


  1. Federal Highway Administration (2009). "Section 2D.11 Design of Route Signs". Manual on Uniform Traffic Control Devices (2009 2nd revised ed.). Washington, DC: Federal Highway Administration. Guidance: State Route signs...should be rectangular and should be approximately the same size as the U.S. Route sign....The shape of the white area should be circular in the absence of any determination to the contrary by the individual State concerned.
  2. "County Roads". Hampshire Council of Governments. Retrieved August 16, 2017.
  3. "The Yellowstone Trail". South Milwaukee, Wisconsin. Archived from the original on June 8, 2005. Retrieved June 8, 2007.
  4. Weingroff, Richard F. (November 18, 2015). "From Names to Numbers: The Origins of the U.S. Numbered Highway System". Federal Highway Administration. Retrieved November 18, 2015.