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 extends throughout the contiguous United States and has routes in Hawaii, Alaska, and Puerto Rico.
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.
U.S. Route 12 or U.S. Highway 12 (US 12) is an east–west United States Numbered Highway, running from Aberdeen, Washington, to Detroit, Michigan, for almost 2,500 miles (4,000 km). The highway has mostly been superseded by Interstate 90 (I-90) and I-94, but, unlike most U.S. Highways that have been superseded by an Interstate, US 12 remains as an important link for local and regional destinations. The highway's western terminus in Aberdeen is at an intersection with US 101, while the highway's eastern terminus in Downtown Detroit is at the corner of Michigan and Cass avenues, near Campus Martius Park.
U.S. Route 75 is a north–south U.S. Highway that runs 1,239 miles (1,994 km) in the central United States. The highway's northern terminus is located at Noyes, Minnesota, which connects to the Canadian border, where it once continued as Manitoba Highway 75 on the other side of the now-closed border crossing. Its southern terminus is located at Interstate 30 (I-30) and I-45 in Dallas, Texas, where it is known as North Central Expressway.
U.S. Highway 16 (US 16) is an east–west United States Numbered Highway between Rapid City, South Dakota, and Yellowstone National Park in Wyoming. The highway's eastern terminus is at a junction with Interstate 90 (I-90)/US 14, concurrent with I-190, in Rapid City. The western terminus is the east entrance to Yellowstone National Park, concurrent with US 14 and US 20. US 16 used to extend all the way to Michigan but has been truncated in favor of I-90 and I-96.
U.S. Highway 218 (US 218) is an original United States Highway that was created in 1926. Although technically a spur of US 18, US 218 neither begins nor ends at US 18, but overlaps US 18 for eight miles (13 km) near Charles City, Iowa. US 218 begins at U.S. 136 in downtown Keokuk and ends 319 miles (513 km) away at Interstate 35 (I-35) and US 14 at Owatonna, Minnesota. A large portion of US 218 in Iowa is part of the Avenue of the Saints, which connects St. Louis, Missouri, and Saint Paul, Minnesota.
A routenumber, designation or abbreviation 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.
Minnesota State Highway 5 is a 76.347-mile-long (122.869 km) highway in Minnesota, which runs from its intersection with MN 19 and MN 22 in Gaylord and continues east and northeast to its eastern terminus at its intersection with MN 120 in Maplewood. The route passes through downtown Saint Paul.
A concurrency in a road network is an instance of one physical roadway bearing two or more different route numbers. When two roadways share the same right-of-way, it is sometimes called a common section or commons. Other terminology for a concurrency includes overlap, coincidence, duplex, triplex, multiplex, dual routing or triple routing.
A business route in the United States is a short special route that branches off a parent numbered highway at its beginning, continues through the central business district of a nearby city or town, and finally reconnects with the same parent numbered highway at the business route's end. Their designation is often intended to direct traffic to the business districts bypassed when a new highway is constructed some distance away.
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 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 four types of roads designated as Routes are:
The New Hampshire Highway System is the public roads system of the U.S. state of New Hampshire containing approximately 17,029 miles (27,406 km) maintained by the New Hampshire Department of Transportation (NHDOT). All public roads in the state are called "highways", thus there is no technical distinction between a "road" or a "highway" in New Hampshire.
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.
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 Interstate Highway System, U.S. highway system, and several state highway systems. Each type of special route possesses generally defined characteristics and has a defined relationship with its parent route. Typically, special routes share a route number with a dominant route, often referred as the "parent" or "mainline", and are given either a descriptor which may be used either before or after the route name, such as Alternate or Business, or a letter suffix that is attached to the route number. For example, an alternate route of U.S. Route 1 may be called "Alternate U.S. Route 1", "U.S. Route 1 Alternate", or "U.S. Route 1A". Occasionally, a special route will have both a descriptor and a suffix, such as U.S. Route 1A Business.
There are at least thirteen current and three former special routes of U.S. Route 27.
The primary highway system makes up over 9,000 miles (14,000 km), approximately 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. Highway 30 at 332 miles (534 km). The shortest highway is Interstate 129 at 0.27 miles (430 m).
County roads in Minnesota are roads locally maintained by county highway departments in Minnesota. County roads span a wide variety of road types, varying from A-minor arterials that carry large volumes of traffic to gravel roads.
The Arkansas Highway System is made up of all the highways designated as Interstates, U.S. Highways and State Highways in the US state of Arkansas. The system is maintained by the Arkansas Department of Transportation (ArDOT), known as the Arkansas State Highway Department (AHD) until 1977 and the Arkansas State Highway and Transportation Department (AHTD) from 1977 to 2017. The system contains 16,442.90 miles (26,462.28 km) of Interstates, U.S. Routes, state highways, and special routes. The shortest members are unsigned state highways Arkansas Highway 806 and Arkansas Highway 885, both 0.09 miles (0.14 km) in length. The longest route is U.S. Route 67, which runs 296.95 miles (477.89 km) from Texarkana to Missouri.
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.
