Автомобильные дороги США: Система федеральных трасс

Highway system of the United States of America
a set of roads typically called U. S. Routes or U. S. Highways

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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 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. The route numbers and locations are coordinated by the American Association of State Highway and Transportation Officials (AASHTO).|group=lower alpha Three digit numbered highways are generally spur routes of parent highways; for example, U. S. Route 264 (US 264) is a spur off US 64. Some divided routes, such as US 19E and US 19W, exist to provide two alignments for one route. Special routes, which can be labeled as alternate, bypass or business, depending on the intended use, provide a parallel routing to the mainline U. S. Highway. Before the U. S. Routes were designated, auto trails designated by auto trail associations were the main means of marking roads through the United States. These were private organizations, and the system of road marking at the time was haphazard and not uniform. In 1925, the Joint Board on Interstate Highways, recommended by the American Association of State Highway Officials (AASHO), worked to form a national numbering system to rationalize the roads. After several meetings, a final report was approved by the U. S. Department of Agriculture in November 1925. After getting feedback from the states, they made several modifications; the U. S. Highway System was approved on November 11, 1926. Expansion of the U. S. Highway System continued until 1956, when the Interstate Highway System was laid out and began construction under the administration of President Dwight D. Eisenhower. After the national implementation of the Interstate Highway System, many U. S. Routes that had been bypassed or overlaid with Interstate Highways were decommissioned and removed from the system. In some places, the U. S. Routes remain alongside the Interstates and serve as a means for interstate travelers to access local services and as secondary feeder roads or as important major arteries in their own right. In other places, where there are no nearby Interstate Highways, the U. S. Routes often remain as the most well developed roads for long distance travel. While the system's growth has slowed in recent decades, the U. S. Highway System remains in place to this day and new routes are occasionally added to the system.

In general, U. S. Routes do not have a minimum design standard, unlike the later Interstate Highways, and are not usually built to freeway standards. Some stretches of U. S. Routes do meet those standards. Many are designated using the main streets of the cities and towns through which they run. New additions to the system, however, must "substantially meet the current AASHTO design standards". US 51 uses part of the Jane Addams Memorial Tollway in Illinois; the old road is Illinois Route 251. US 278 uses the tolled Cross Island Parkway in South Carolina; the old road is US 278 Business. The tolls were removed in July 2021. US 301 is a toll road through Delaware; the former routing is a free road and uses several Delaware state routes. US 412 uses the Cimarron Turnpike in Oklahoma; the old road is US 64. US 412 also uses the Cherokee Turnpike in Oklahoma; the old road is US 412 Alternate.

U. S. Routes in the contiguous United States follow a grid pattern, in which odd numbered routes run generally north to south and even numbered routes run generally east to west, though three digit spur routes can be either or. Usually, one and two digit routes are major routes, and three digit routes are numbered as shorter spur routes from a main route. Odd numbers generally increase from east to west; U. S. Route 1 (US 1) follows the Atlantic Coast and US 101 follows the Pacific Coast. (US 101 is one of the many exceptions to the standard numbering grid; its first "digit" is "10", and it is a main route on its own and not a spur of US 1.) Even numbers tend to increase from north to south; US 2 closely follows the Canadian border, and US 98 hugs the Gulf Coast. The longest routes connecting major cities are generally numbered to end in a 1 or a 0; however, extensions and truncations have made this distinction largely meaningless. These guidelines are very rough, and exceptions to all of the basic numbering rules exist. The numbering system also extended beyond the borders of the United States in an unofficial manner. Many Canadian highways were renumbered in the 1940s and 1950s to adopt the same number as the U. S. Route they connected to – mostly in the western provinces. Examples include British Columbia's highways 93, 95, 97, and 99; Manitoba's highways 59, 75, and 83; or 71. The reverse happened with U. S. Route 57, originally a Texas state highway numbered to match Mexican Federal Highway 57. In the 1950s, the numbering grid for the new Interstate Highway System was established as intentionally opposite from the US grid insofar as the direction the route numbers increase. Interstate Highway numbers increase from west to east and south to north, to keep identically numbered routes geographically apart in order to keep them from being confused with one another, Not all spurs travel in the same direction as their "parents"; some are connected to their parents only by other spurs, or not at all, instead only traveling near their parents, Also, a spur may travel in different cardinal directions than its parent, such as US 522, which is a north–south route, unlike its parent US 22, which is east–west. As originally assigned, the first digit of the spurs increased from north to south and east to west along the parent; for example, US 60 had spurs, running from east to west, designated as US 160 in Missouri, US 260 in Oklahoma, US 360 in Texas, and US 460 and US 560 in New Mexico. AASHTO guidelines specifically prohibit Interstate Highways and U. S. Routes from sharing a number within the same state. Each state manufactures their own signage, and as such subtle variations exist all across the United States. Individual states may use cut out or rectangular designs, some have black outlines, and California prints the letters "US" above the numerals. One and two digit shields generally feature the same large, bold numerals on a square dimension shield, while 3 digit routes may either use the same shield with a narrower font, or a wider rectangular dimension shield. Special routes may be indicated with a banner above the route number, or with a letter suffixed to the route number. Signs are generally displayed in several different locations. First, they are shown along the side of the route at regular intervals or after major intersections (called reassurance markers), which shows the route and the nominal direction of travel. Second, they are displayed at intersections with other major roads, so that intersecting traffic can follow their chosen course. Third, they can be displayed on large green guide signs that indicate upcoming interchanges on freeways and expressways. its current policy is to deny approval of new split routes and to eliminate existing ones "as rapidly as the State Highway Department and the Standing Committee on Highways can reach agreement with reference thereto". The use of U. S. Route or U. S. Highway on a local level depends on the state, with some states such as Delaware using "route" and others such as Colorado using "highway".

In 1903, Horatio Nelson Jackson became the first documented person to drive an automobile from San Francisco to New York using only a connection of dirt roads, cow paths, and railroad beds. His journey, covered by the press, became a national sensation and called for a system of long distance roads. In the early 1910s, auto trail organizations—most prominently the Lincoln Highway—began to spring up, marking and promoting routes for the new recreation of long distance automobile travel. The Yellowstone Trail was another of the earliest examples. While many of these organizations worked with towns and states along the route to improve the roadways, others simply chose a route based on towns that were willing to pay dues, put up signs, and did little else.

Wisconsin was the first state in the U. S. to number its highways, erecting signs in May 1918. Behind the scenes, the federal aid program had begun with the passage of the Federal Aid Road Act of 1916, providing 50% monetary support from the federal government for improvement of major roads. The Federal Aid Highway Act of 1921 limited the routes to 7% of each state's roads, while 3 in every 7 roads had to be "interstate in character". Identification of these main roads was completed in 1923. AASHO recommended that the Secretary of Agriculture work with the states to designate these routes. based on the shield found on the Great Seal of the United States.

The new system was both praised and criticized by local newspapers, often depending on whether that city was connected to a major route. While the Lincoln Highway Association understood and supported the plan, partly because they were assured of getting the US 30 designation as much as possible, most other trail associations lamented their obsolescence. At their January 14–15, 1926 meeting, AASHO was flooded with complaints. By the time the first route log was published in April 1927, major numbering changes had been made in Pennsylvania in order to align the routes to the existing auto trails. In addition, U. S. Route 15 had been extended across Virginia. Much of the early criticism of the U. S. Highway System focused on the choice of numbers to designate the highways, rather than names. Some thought a numbered highway system to be cold compared to the more colorful names and historic value of the auto trail systems. The New York Times wrote, "The traveler may shed tears as he drives the Lincoln Highway or dream dreams as he speeds over the Jefferson Highway, but how can he get a 'kick' out of 46, 55 or 33 or 21?" (A popular song later promised, "Get your kicks on Route 66!") The writer Ernest McGaffey was quoted as saying, "Logarithms will take the place of legends, and 'hokum' for history." the Pasadena Freeway carried US 66, and the Pulaski Skyway carries US 1 and US 9.

The Federal Aid Highway Act of 1956 appropriated funding for the Interstate Highway System, to construct a vast network of freeways across the country. By 1957, AASHO had decided to assign a new grid to the new routes, to be numbered in the opposite directions as the U. S. Highway grid. Though the Interstate numbers were to supplement—rather than replace—the U. S. Route numbers, in many cases (especially in the West) the US highways were rerouted along the new Interstates. A few major connections not served by Interstate Highways include US 6 from Hartford, Connecticut, to Providence, Rhode Island and US 93 from Phoenix, Arizona to Las Vegas, Nevada, though the latter is planned to be upgraded to Interstate 11. Three state capitals in the contiguous U. S. are served only by U. S. Routes: Dover, Delaware; Jefferson City, Missouri; and Pierre, South Dakota. In 1995, the National Highway System was defined to include both the Interstate Highway System and other roads designated as important to the nation's economy, defense, and mobility. AASHTO is in the process of eliminating all intrastate U. S. Highways less than 300 mile (483 km) in length "as rapidly as the State Highway Department and the Standing Committee on Highways of the American Association of State Highway and Transportation Officials can reach agreement with reference thereto". New additions to the system must serve more than one state and "substantially meet the current AASHTO design standards".