A road is a thoroughfare for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets , whose primary function is to serve as public spaces, the main function of roads is transportation.
132-531: 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
264-400: A road use tax , is payable on some vehicles used on the public road. The definition of a road depends on the definition of a highway; there is no formal definition for a highway in the relevant Act. A 1984 ruling said "the land over which a public right of way exists is known as a highway; and although most highways have been made up into roads, and most easements of way exist over footpaths,
396-411: A single carriageway road is converted into dual carriageway by building a second separate carriageway alongside the first, it is usually referred to as duplication , twinning or doubling . The original carriageway is changed from two-way to become one-way, while the new carriageway is one-way in the opposite direction. In the same way as converting railway lines from single track to double track ,
528-407: A "B" suffix. Most business routes are the former alignments of their parent. Bypass routes (rarely known as "Relief routes") typically go around population centers and are newer and faster than their mainline and/or business route counterparts. In some cases, due to urban sprawl over time, land around bypasses can become developed, expanding the population center outward and creating a misnomer with
660-457: A 25 to 50 millimeter hole through the pavement into the sub-base with a dry-bit roto-hammer . Next, a two-part epoxy is poured into the hole – dyed for visual clarity. Once the epoxy hardens, technicians drill through the hole. If a void is present, the epoxy will stick to the core and provide physical evidence. Common stabilization materials include pozzolan -cement grout and polyurethane. The requirements for slab stabilization are strength and
792-614: A May 2009 report by the American Association of State Highway and Transportation Officials (AASHTO) and TRIP – a national transportation research organization – driving on rough roads costs the average American motorist approximately $ 400 a year in extra vehicle operating costs. Drivers living in urban areas with populations more than 250,000 are paying upwards of $ 750 more annually because of accelerated vehicle deterioration, increased maintenance, additional fuel consumption , and tire wear caused by poor road conditions. When
924-423: A banner such as alternate or bypass —are also managed by AASHTO. These are sometimes designated with lettered suffixes, like A for alternate or B for business. The official route log, last published by AASHTO in 1989, has been named United States Numbered Highways since its initial publication in 1926. Within the route log, "U.S. Route" is used in the table of contents, while "United States Highway" appears as
1056-412: A city which provides the traveling public an opportunity to travel through that city, passing through the business part of the city; while the regular number is used to obviate passing through the congested part of the city. This "Business Route" connects with the regular numbered route at the opposite side of the city limits. AASHTO defines bypass or relief routes for U.S. highways as: ...a route which
1188-550: A complete radial around an area, having at least one intersection with the parent route. Because of their circumferential nature, inner/outer directions have been used to sign such routes, as opposed to cardinal directions , though this convention is not universally followed (Arizona Loops 101 , 202 , and 303 in the Phoenix metropolitan area do not follow such convention, and are signed with cardinal directions based on their local orientation). Georgia State Route 10 Loop , which
1320-549: A different settlements or different city neighborhoods than the parent route, but roughly remain parallel to the parent. Unlike business routes and bypasses, their relationship to population centers varies from case to case. Alternates also can be quite longer than most other special routes with some spanning over 50 miles (e.g. US 1A in Maine and US 74A in North Carolina ). Prior to 1960 there were "optional" routes in
1452-519: A distinctively-shaped white shield with large black numerals in the center. Often, the shield is displayed against a black square or rectangular background. 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
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#17327725067411584-419: A double-wheeled, steel roller to insert the rod to the desired depth. After inserting the backer rod, the sealant is placed into the joint. There are various materials to choose for this method including hot pour bituminous liquid, silicone and preformed compression seals. Careful design and construction of roads can increase road traffic safety and reduce the harm (deaths, injuries, and property damage) on
1716-486: A long-term detour until the parent route's planned path is completed, at which point the Temporary designation is either removed or replaced by another designation such as Alternate or Business. Temporary routes generally traverse along roads of a lower standard than the planned mainline. An example is US 191 through a copper mine north of Clifton, Arizona . AASHTO defines and specifies that temporary routes should have
1848-623: 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
1980-413: A major two-level (and at one point, three-level) roadway in the downtown area, are being rebuilt with a designed service life of 100 years. Virtually all roads require some form of maintenance before they come to the end of their service life. Pro-active agencies use pavement management techniques to continually monitor road conditions and schedule preventive maintenance treatments as needed to prolong
2112-441: 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
2244-491: A parent route that traverse through an area of natural or historical significance. Only one route in the country remains with the official Scenic designation: US 40 Scenic . Toll routes, in terms of special routes, are loops that are faster than the parent route, but are tolled . The other usage with the promulgation of the 2009 MUTCD is to use a new yellow toll plate above the marker along tolled segments of highways. Loop routes, in terms of special routes, are loops that form
2376-771: A part of popular culture. US 101 continues east and then south to end at Olympia, Washington . The western terminus of US 2 is now at Everett, Washington . Road There are many types of roads , including parkways , avenues , controlled-access highways (freeways, motorways, and expressways), tollways , interstates , highways , thoroughfares , and local roads. The primary features of roads include lanes , sidewalks (pavement), roadways (carriageways), medians , shoulders , verges , bike paths (cycle paths), and shared-use paths . Historically many roads were simply recognizable routes without any formal construction or some maintenance. The Organization for Economic Co-operation and Development (OECD) defines
2508-428: A road as "a line of communication (travelled way) using a stabilized base other than rails or air strips open to public traffic, primarily for the use of road motor vehicles running on their own wheels", which includes "bridges, tunnels, supporting structures, junctions, crossings, interchanges, and toll roads, but not cycle paths". The Eurostat , ITF and UNECE Glossary for Transport Statistics Illustrated defines
2640-494: A road as a "Line of communication (traveled way) open to public traffic, primarily for the use of road motor vehicles, using a stabilized base other than rails or air strips. [...] Included are paved roads and other roads with a stabilized base, e.g. gravel roads. Roads also cover streets, bridges, tunnels, supporting structures, junctions, crossings and interchanges. Toll roads are also included. Excluded are dedicated cycle lanes." The 1968 Vienna Convention on Road Traffic defines
2772-510: A road as the entire surface of any way or street open to public traffic. In urban areas roads may diverge through a city or village and be named as streets, serving a dual function as urban space easement and route. Modern roads are normally smoothed, paved, or otherwise prepared to allow easy travel . Part 2, Division 1, clauses 11–13 of the National Transport Commission Regulations 2006 defines
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#17327725067412904-524: A road in Australia as 'an area that is open to or used by the public and is developed for, or has as one of its main uses, the driving or riding of motor vehicles.' Further, it defines a shoulder (typical an area of the road outside the edge line, or the curb) and a road-related area which includes green areas separating roads, areas designated for cyclists and areas generally accessible to the public for driving, riding or parking vehicles. In New Zealand,
3036-600: A rough grid. Major routes from the earlier map were assigned numbers ending in 0, 1 or 5 (5 was soon relegated to less-major status), and short connections received three-digit numbers based on the main highway from which they spurred. The five-man committee met September 25, and submitted the final report to the Joint Board secretary on October 26. The board sent the report to the Secretary of Agriculture on October 30, and he approved it November 18, 1925. The new system
3168-426: Is Pennsylvania Route 82 Alternate Truck which bypasses a weight-restricted bridge over East Branch of Red Clay Creek. Most of the alternate truck routes were signed in 2013, though some were signed as recently as 2023. Alternate routes are loops that provide alternative alignment for a parent route. They are usually signed with an " alternate " or " alt " auxiliary or an "A" suffix. They generally traverse through
3300-432: Is 40 years for new bitumen and concrete pavement. Maintenance is considered in the whole life cost of the road with service at 10, 20 and 30-year milestones. Roads can be and are designed for a variety of lives (8-, 15-, 30-, and 60-year designs). When pavement lasts longer than its intended life, it may have been overbuilt, and the original costs may have been too high. When a pavement fails before its intended design life,
3432-433: Is a non-destructive method of solving this problem and is usually employed with other concrete pavement restoration methods including patching and diamond grinding. The technique restores support to concrete slabs by filing small voids that develop underneath the concrete slab at joints, cracks or the pavement edge. The process consists of pumping a cementitious grout or polyurethane mixture through holes drilled through
3564-636: 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 . As with
3696-694: Is also an example of a route with three special route designations. U.S. Route 30 Business Alternate Truck provides an alternate truck bypass of U.S. Route 30 Business in Downingtown, Pennsylvania . Routes with special designations in the U.S. have typical behavior that distinguishes them from other routes. There are, however, many exceptions to the common behavior, depending on the situation. Business routes (also known as city routes) can be loops or spurs and generally traverse through or near population centers (usually towns and small cities). They are usually signed with " business " or " bus " auxiliaries or
3828-487: Is also common. Some road fixtures such as road signs and fire hydrants are designed to collapse on impact. Light poles are designed to break at the base rather than violently stop a car that hits them. Highway authorities may also remove larger trees from the immediate vicinity of the road. During heavy rains, if the elevation of the road surface is not higher than the surrounding landscape, it may result in flooding. Speed limits can improve road traffic safety and reduce
3960-485: Is another common procedure used to locate voids. It is recommended to do this testing at night as during cooler temperatures, joints open, aggregate interlock diminishes and load deflections are at their highest. Ground penetrating radar pulses electromagnetic waves into the pavement and measures and graphically displays the reflected signal. This can reveal voids and other defects. The epoxy/core test, detects voids by visual and mechanical methods. It consists of drilling
4092-418: Is discovered it is removed, moisture content is managed and replaced with standard fill compacted to meet the design requirements (generally 90–95% relative compaction). Blasting is not frequently used to excavate the roadbed as the intact rock structure forms an ideal road base. When a depression must be filled to come up to the road grade the native bed is compacted after the topsoil has been removed. The fill
United States Numbered Highway System - Misplaced Pages Continue
4224-454: Is established for the purpose of designating a route which entirely by-passes a city or congested area and joins in with the regular numbered route beyond the city or congested area. AASHTO defines a category of special routes separate from primary and auxiliary Interstate designations known as Interstate Business routes. These routes do not have to comply to Interstate construction standards, but are routes that may be identified and approved by
4356-640: Is impassable, due to either a traffic jams , traffic collision , or road closure (for a variety of reasons). Emergency U.S. Route 31 , which offers an alternative crossing of the Grand River in case the bascule bridge in Grand Haven , Michigan is unavailable for motorists, is one such route. According to the Michigan Department of Transportation , "This route would only be used in emergency situations and worst-case scenarios impacting
4488-770: Is in the process of eliminating all intrastate U.S. Highways less than 300 miles (480 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 ". A version of this policy has been in place since 1937. The original major transcontinental routes in 1925, along with
4620-451: Is made by the "compacted layer method" where a layer of fill is spread then compacted to specifications, under saturated conditions. The process is repeated until the desired grade is reached. General fill material should be free of organics , meet minimum California bearing ratio (CBR) results and have a low plasticity index . The lower fill generally comprises sand or a sand-rich mixture with fine gravel, which acts as an inhibitor to
4752-500: Is marked, that the shorter and better constructed route be given the regular number and the other section designated as the "Alternate Route". It is further recommended that the Highway Department erect signs at the junction points of the regular and alternate routes giving the distance between the cities or points concerned... In no instance should an alternate routing be used for the purpose of keeping an obsolete section on
4884-440: Is not all-encompassing however, as not all special routes have these sign plates. The American Association of State Highway and Transportation Officials (AASHTO) sets the nationwide precedent for special routes, particularly for U.S. Numbered Highways . As of 2009, the standards organization only advocates four types of special routes: business, bypass, alternate, and temporary. AASHTO suggests that transportation authorities of
5016-571: Is primarily due to environmental effects such as frost heaves , thermal cracking and oxidation often contribute, however accumulated damage from vehicles also contributes. According to a series of experiments carried out in the late 1950s, called the AASHO Road Test , it was empirically determined that the effective damage done to the road is roughly proportional to the fourth power of axle weight . A typical tractor-trailer weighing 80,000 pounds (36.287 t ) with 8,000 pounds (3.629 t) on
5148-522: Is some ambiguity between the terms highway and road . For the purposes of the English law , Highways Act 1980 , which covers England and Wales but not Scotland or Northern Ireland , road is "any length of highway or of any other road to which the public has access, and includes bridges over which a road passes". This includes footpaths, bridleways and cycle tracks, and also road and driveways on private land and many car parks. Vehicle Excise Duty ,
5280-410: Is taken to preserve reference Benchmarks Roads are designed and built for primary use by vehicular and pedestrian traffic. Storm drainage and environmental considerations are a major concern. Erosion and sediment controls are constructed to prevent detrimental effects. Drainage lines are laid with sealed joints in the road easement with runoff coefficients and characteristics adequate for
5412-546: Is the native material underneath a constructed road. Road construction requires the creation of an engineered continuous right-of-way or roadbed , overcoming geographic obstacles and having grades low enough to permit vehicle or foot travel , and may be required to meet standards set by law or official guidelines. The process is often begun with the removal of earth and rock by digging or blasting, construction of embankments , bridges and tunnels , and removal of vegetation (this may involve deforestation ) and followed by
United States Numbered Highway System - Misplaced Pages Continue
5544-476: Is the perimeter highway around Athens, Georgia , and the former Georgia State Route 120 Loop , which encircled a section of Marietta, Georgia , are two examples. Loop routes are common throughout Texas; see List of state highway loops in Texas . Temporary routes complete a gap between two segments of a parent route that exists because the parent route through the area has not been fully constructed. They serve as
5676-559: Is usually stripped and stockpiled nearby for rehabilitation of newly constructed embankments along the road. Stumps and roots are removed and holes filled as required before the earthwork begins. Final rehabilitation after road construction is completed will include seeding, planting, watering and other activities to reinstate the area to be consistent with the untouched surrounding areas. Processes during earthwork include excavation, removal of material to spoil, filling, compacting, construction and trimming. If rock or other unsuitable material
5808-495: 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
5940-531: The American Association of State Highway and Transportation Officials (AASHTO). The only federal involvement in AASHTO is a nonvoting seat for the United States Department of Transportation . Generally, most north-to-south highways are odd-numbered, with the lowest numbers in the east and the highest in the west, while east-to-west highways are typically even-numbered, with the lowest numbers in
6072-503: The Everett Turnpike . However, US Routes in the system do use parts of five toll roads: 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
6204-685: The Gulf Freeway carried US 75 , 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
6336-539: 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
6468-410: 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
6600-617: The New England states got together to establish the six-state New England Interstate Routes . 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
6732-536: The Pacific coast . Many local disputes arose related to the committee's choices between designation of two roughly equal parallel routes, which were often competing auto trails. At their January meeting, AASHO approved the first two of many split routes (specifically US 40 between Manhattan, Kansas and Limon, Colorado and US 50 between Baldwin City, Kansas and Garden City, Kansas ). In effect, each of
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#17327725067416864-413: The auto trails which they roughly replaced, were as follows: US 10, US 60, and US 90 only ran about two thirds of the way across the country, while US 11 and US 60 ran significantly diagonally. US 60's violation of two of the conventions would prove to be one of the major sticking points; US 60 eventually was designated as US 66 in 1926, and later it became
6996-406: The land zoning and storm water system. Drainage systems must be capable of carrying the ultimate design flow from the upstream catchment with approval for the outfall from the appropriate authority to a watercourse , creek , river or the sea for drainage discharge. A borrow pit (source for obtaining fill, gravel, and rock) and a water source should be located near or in reasonable distance to
7128-406: 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 Ontario King's Highway 71 . The reverse happened with U.S. Route 57 , originally a Texas state highway numbered to match Mexican Federal Highway 57 . In the 1950s,
7260-482: 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
7392-601: The Northeast, New York held out for fewer routes designated as US highways. The Pennsylvania representative, who had not attended the local meetings, convinced AASHO to add a dense network of routes, which had the effect of giving six routes termini along the state line. (Only US 220 still ends near the state line, and now it ends at an intersection with future I-86 .) Because US 20 seemed indirect, passing through Yellowstone National Park , Idaho and Oregon requested that US 30 be swapped with US 20 to
7524-472: The State Highway Department and the Standing Committee on Highways can reach agreement". This policy was adopted by 1996; however, many of these routes still exist, mostly in Tennessee . Originally in the United States, the terms used for special routes were "City", "Truck", and "Optional". In 1959–1960, the terms were changed to "Business", "Bypass", and "Alternate", respectively; however, the "Truck" banner
7656-750: 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. Major decommissioning of former routes began with California 's highway renumbering in 1964 . The 1985 removal of US 66 is often seen as the end of an era of US highways. 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
7788-572: The U.S. numbered system after a new routing has been constructed and available to traffic. Spur routes split away from the parent route without returning. They usually end in a settlement or area not served by the parent. Connector routes are spurs that connect the parent route with a nearby prominent route, usually an Interstate highway (e.g. Connector M-44 [Conn. M-44] connects M-44 to I-96 ). Both Spurs and Connectors are generally very short in length, not spanning more than ten miles (16 km). Scenic routes, in terms of special routes, are loops of
7920-534: The US Highway system, three-digit numbers are assigned to spurs of one or two-digit routes. US 201 , for example, splits from US 1 at Brunswick, Maine , and runs north to Canada. 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
8052-474: The US highway, which did not end in zero, but was still seen as a satisfyingly round number. Route 66 came to have a prominent place in popular culture, being featured in song and films. With 32 states already marking their routes, the plan was approved by AASHO on November 11, 1926. This plan included a number of directionally split routes, several discontinuous routes (including US 6 , US 19 and US 50 ), and some termini at state lines. By
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#17327725067418184-651: The United States Numbered Highways system had a total length of 157,724 miles (253,832 km). Except for toll bridges and tunnels , very few U.S. Routes are toll roads . AASHTO policy says that a toll road may only be included as a special route , and that "a toll-free routing between the same termini shall continue to be retained and marked as a part of the U.S. Numbered System." U.S. Route 3 (US 3) meets this obligation; in New Hampshire , it does not follow tolled portions of
8316-524: The United States remove other types of special routes and/or replace such obsolete designations with another type of route. Some old alignments of routes may also be informally known as special routes (despite some that do not intersect the parent route). These older alignments may be given street names like "Old U.S. Highway 52", or in some rare cases, be signed with route shields attached to "Old" or "Historic" sign plates (such as decommissioned sections of former U.S. Route 66 that are still driveable). In
8448-432: The United States that were synonymous with alternate routes. As a means of providing uniformity, the "Optional" term was phased out in the 1960s. AASHTO defines and specifies that alternate routes should have the following behavior: An "Alternate Route" shall be considered a route which starts at a point where it branches off from the main numbered route, may pass through certain cities and towns, and then connect back with
8580-422: The ability to flow into or expand to fill small voids. Colloidal mixing equipment is necessary to use the pozzolan-cement grouts. The contractor must place the grout using a positive-displacement injection pump or a non-pulsing progressive cavity pump. A drill is also necessary but it must produce a clean hole with no surface spalling or breakouts. The injection devices must include a grout packer capable of sealing
8712-480: The approval of the states along the former US 60. But Missouri and Oklahoma did object—Missouri had already printed maps, and Oklahoma had prepared signs. A compromise was proposed, in which US 60 would split at Springfield, Missouri , into US 60E and US 60N, but both sides objected. The final solution resulted in the assignment of US 66 to the Chicago-Los Angeles portion of
8844-412: The association. The same route marking policy applies to both U.S. Numbered Highways and Interstate highways; however, business route designations are sometimes used for Interstate highways. Known as Business Loops and Business Spurs , these routes that principally travel through the corporate limits of a city, passing through the central business district of the city. Business routes are used when
8976-404: The auto trail associations were not able to formally address the meetings. However, as a compromise, they talked with the Joint Board members. The associations finally settled on a general agreement with the numbering plans, as named trails would still be included. The tentative system added up to 81,000 miles (130,000 km), 2.8% of the public road mileage at the time. The second full meeting
9108-521: The average US motorist pays about $ 335/year. In contrast, the average motorist pays about $ 171/year in road maintenance taxes (based on 600 gallons/year and $ 0.285/gallon tax). Distress and serviceability loss on concrete roads can be caused by loss of support due to voids beneath the concrete pavement slabs. The voids usually occur near cracks or joints due to surface water infiltration . The most common causes of voids are pumping, consolidation, subgrade failure and bridge approach failure. Slab stabilization
9240-478: The case of U.S. state route systems, special routes are generally restricted to primary state routes, not secondary state routes, though Missouri has three supplemental routes with short spur routes, and the 500-series county routes in New Jersey have alternate, bypass, spur, and truck routes. A few highways have two special route designations. Some of these doubly designated special routes are: There
9372-551: The definition of a road is broad in common law where the statutory definition includes areas the public has access to, by right or not. Beaches, publicly accessible car parks and yards (even if privately owned), river beds, road shoulders (verges), wharves and bridges are included. However, the definition of a road for insurance purposes may be restricted to reduce risk. In the United Kingdom The Highway Code details rules for "road users", but there
9504-465: The design structural capacity, stop erosion or eliminate faulting. It does, however, restore the slab support, therefore, decreasing deflections under the load. Stabilization should only be performed at joints and cracks where the loss of support exists. Visual inspection is the simplest manner to find voids. Signs that repair is needed are transverse joint faulting, corner breaks and shoulder drop off and lines at or near joints and cracks. Deflection testing
9636-400: The entire bridge structure." Emergency Interstate 94 follows Interstate 94 throughout much of southern Michigan. Ontario , Canada is one jurisdiction outside the United States with a very prevalent system of these roads. Other governments have a variation on this concept, though not always a "special route": Some U.S. Routes are given directional suffixes to indicate a split of
9768-470: 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
9900-441: The first pathways were the trails made by animals has not been universally accepted; in many cases animals do not follow constant paths. Some believe that some roads originated from following animal trails. The Icknield Way may exemplify this type of road origination, where human and animal both selected the same natural line. By about 10,000 BC human travelers used rough roads/pathways. In transport engineering , subgrade
10032-483: The following behavior: In the erection of signs for numbering routes, it is necessary in some cases to carry a number temporarily over a road that ultimately will not be the permanent location of that number. Great care should be taken by the State Highway Departments in seeing that when numbers of this character are permitted, that a standard strip carrying the words "Temporary" shall be placed on
10164-416: The functional condition of the road while reducing the need for routing maintenance, leading to extended service life without increasing structural capacity. Older concrete pavements that develop faults can be repaired with a dowel bar retrofit , in which slots are cut in the pavement at each joint, and dowel bars are placed in the slots, which are then filled with concrete patching material. This can extend
10296-464: The growth of plants or other vegetable matter. The compacted fill also serves as lower-stratum drainage. Select second fill ( sieved ) should be composed of gravel , decomposed rock or broken rock below a specified particle size and be free of large lumps of clay . Sand clay fill may also be used. The roadbed must be "proof rolled" after each layer of fill is compacted. If a roller passes over an area without creating visible deformation or spring
10428-514: The heading for each route. All reports of the Special Committee on Route Numbering since 1989 use "U.S. Route", and federal laws relating to highways use "United States Route" or "U.S. Route" more often than the "Highway" variants. 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
10560-404: The highway system from traffic collisions. On neighborhood roads traffic calming , safety barriers , pedestrian crossings and cycle lanes can help protect pedestrians, cyclists, and drivers. Lane markers in some countries and states are marked with Cat's eyes or Botts dots. Botts dots are not used where it is icy in the winter, because frost and snowplows can break the glue that holds them to
10692-580: The hole. The injection device must also have a return hose or a fast-control reverse switch, in case workers detect slab movement on the uplift gauge. The uplift beam helps to monitor the slab deflection and has to have sensitive dial gauges. Also called joint and crack repair, this method's purpose is to minimize infiltration of surface water and incompressible material into the joint system. Joint sealants are also used to reduce dowel bar corrosion in concrete pavement restoration techniques. Successful resealing consists of old sealant removal, shaping and cleaning
10824-467: 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
10956-478: 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
11088-404: The laying of pavement material. A variety of road building equipment is employed in road building. After design, approval , planning , legal, and environmental considerations have been addressed alignment of the road is set out by a surveyor . The radii and gradient are designed and staked out to best suit the natural ground levels and minimize the amount of cut and fill. Great care
11220-410: The life of the concrete pavement for 15 years. Failure to maintain roads properly can create significant costs to society. A 2009 report released by the American Association of State Highway and Transportation Officials estimated that about 50% of the roads in the US are in bad condition, with urban areas worse. The report estimates that urban drivers pay an average of $ 746/year on vehicle repairs while
11352-609: The lifespan of their roads. Technically advanced agencies monitor the road network surface condition with sophisticated equipment such as laser/inertial profilometers . These measurements include road curvature , cross slope , asperity , roughness , rutting and texture . Software algorithms use this data to recommend maintenance or new construction. Maintenance treatments for asphalt concrete generally include thin asphalt overlays, crack sealing, surface rejuvenating, fog sealing, micro milling or diamond grinding and surface treatments . Thin surfacing preserves, protects and improves
11484-755: The main route — for instance, U.S. Route 25 splits into U.S. Route 25E (east) and U.S. Route 25W (west) between Newport, Tennessee and North Corbin, Kentucky , and U.S. Route 9W is an alternate of U.S. Route 9 between Fort Lee, New Jersey and Albany, New York . These splits were in the system of United States Numbered Highways from the beginning, and were used when two roughly equivalent routes existed. They are usually loops, but some have been spurs, though since they use directional letter suffixes, they are not generally considered "bannered routes". The American Association of State Highway and Transportation Officials no longer assigns these numbers, and in theory current ones are to be eliminated "as rapidly as
11616-704: The mainline routes that are ill-suited for large truck travel with obstacles (such as low clearance bridges, sharp turns, or steep grades ) or with conditions that could create dangerous situations to smaller vehicles. An example of such a route is U.S. Route 1/9 Truck in New Jersey , which bypasses the segment of U.S. Route 1/9 that uses the Pulaski Skyway , on which trucks are banned. There are alternate truck routes in several counties in southeastern Pennsylvania . They bypass weight-restricted bridges over creeks and rivers. They are mainly routed on major highways and freeways and other roads they intersect to bypass that specific bridge. An example of an alternate truck route
11748-482: 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
11880-515: The new carriageway is not always constructed directly alongside the existing carriageway. Roads that are intended for use by a particular mode of transport can be reallocated for another mode of transport, i.e. by using traffic signs . For instance, in the ongoing road space reallocation effort, some roads (particularly in city centers) which are intended for use by cars are increasingly being repurposed for cycling and/or walking . Like all structures, roads deteriorate over time. Deterioration
12012-514: 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. Other states soon followed. In 1922,
12144-591: The north, and the highest in the south, though the grid guidelines are not rigidly followed, and many exceptions exist. Major north–south routes generally have numbers ending in "1", while major east–west routes usually have numbers ending in "0". 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
12276-477: The number of road traffic casualties from traffic collisions . In their World report on road traffic injury prevention report, the World Health Organization (WHO) identify speed control as one of various interventions likely to contribute to a reduction in road casualties. Road conditions are the collection of factors describing the ease of driving on a particular stretch of road, or on
12408-456: 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, and it omits 50 and 60 which would potentially conflict with US 50 and US 60 . In
12540-491: The optional routes into another route. In 1934, AASHO tried to eliminate many of the split routes by removing them from the log, and designating one of each pair as a three-digit or alternate route, or in one case US 37 . AASHO described its renumbering concept in the October 1934 issue of American Highways : "Wherever an alternate route is not suitable for its own unique two-digit designation, standard procedure assigns
12672-458: The other states. Many states agreed in general with the scope of the system, but believed the Midwest to have added too many routes to the system. The group adopted the shield, with few modifications from the original sketch, at that meeting, as well as the decision to number rather than name the routes. A preliminary numbering system, with eight major east–west and ten major north–south routes,
12804-506: The owner may have excessive repair and rehabilitation costs. Some asphalt pavements are designed as perpetual pavements with an expected structural life in excess of 50 years. Many asphalt pavements built over 35 years ago, despite not being specifically designed as a perpetual pavement, have remained in good condition long past their design life. Many concrete pavements built since the 1950s have significantly outlived their intended design lives. Some roads like Chicago 's Wacker Drive ,
12936-459: The parent route with the use of auxiliary words or suffix letters placed on the route shield or on an adjacent sign, known as a "banner" or "plate" or according to the Manual on Uniform Traffic Control Devices , a "route sign auxiliary sign". A common roadfan synonym for special route is " bannered highway " or " bannered route ", terms coined from the presence of these companion signs. The term
13068-418: The pavement performance, reduce construction costs and decrease maintenance. The completed roadway is finished by paving or left with a gravel or other natural surface. The type of road surface is dependent on economic factors and expected usage. Safety improvements such as traffic signs , crash barriers , raised pavement markers and other forms of road surface marking are installed. According to
13200-411: The place of legends, and 'hokum' for history." When the U.S. numbered system was started in 1925, a few optional routings were established which were designated with a suffixed letter after the number indicating "north", "south", "east", or "west". While a few roads in the system are still numbered in this manner, AASHO believes that they should be eliminated wherever possible, by the absorption of one of
13332-513: The presence or absence of a made road has nothing to do with the distinction. Another legal view is that while a highway historically included footpaths , bridleways , driftways, etc., it can now be used to mean those ways that allow the movement of motor vehicles , and the term rights of way can be used to cover the wider usage. In the United States, laws distinguish between public roads , which are open to public use, and private roads , which are privately controlled. The assertion that
13464-515: The public so that drivers going through a particular area can be aware of hazards that may exist in that area. News agencies, in turn, rely on tips from area residents with respect to certain aspects of road conditions in their coverage area. 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
13596-489: The regular route is directed around the city. They sport green Interstate shields, as opposed to the normal red and blue, with the word "Business" replacing the normal "Interstate" word on the upper portion of the shield. Truck routes were initially known as Bypass routes, and were loops created as a means to divert through truck traffic away from population centers, but the designation was changed to "bypass" in 1959-1960 by AASHTO . Today, Truck routes exist as alternatives for
13728-421: The regular route some miles distant. Since it is the purpose of the U.S. numbered system to mark the best and shortest route available, an alternate route should be designated only where both routes are needed to accommodate the traffic demand, and when the alternate route has substantially the same geometric and structural design standards of the main marked routing. It is recommended that in case an alternate route
13860-418: The reservoir, installing the backer rod and installing the sealant. Sawing, manual removal, plowing and cutting are methods used to remove the old sealant. Saws are used to shape the reservoir. When cleaning the reservoir, no dust, dirt or traces of old sealant should remain. Thus, it is recommended to water wash, sand-blast and then air blow to remove any sand, dirt or dust. The backer rod installation requires
13992-494: The road conditions". Specific aspects of road conditions can be of particular importance for particular purposes. For example, for autonomous vehicles such as self-driving cars , significant road conditions can include "shadowing and lighting changes, road surface texture changes, and road markings consisting of circular reflectors, dashed lines, and solid lines". Various government agencies and private entities, including local news services, track and report on road conditions to
14124-399: The road construction area may be marked for retention. These protected trees should not have the topsoil within the area of the tree's drip line removed and the area should be kept clear of construction material and equipment. Compensation or replacement may be required if a protected tree is damaged. Much of the vegetation may be mulched and put aside for use during reinstatement. The topsoil
14256-512: The road construction site. Approval from local authorities may be required to draw water or for working (crushing and screening) of materials for construction needs. The topsoil and vegetation is removed from the borrow pit and stockpiled for subsequent rehabilitation of the extraction area. Side slopes in the excavation area not steeper than one vertical to two horizontal for safety reasons. Old road surfaces, fences, and buildings may need to be removed before construction can begin. Trees in
14388-473: The road, although they can be embedded in short, shallow trenches carved in the roadway, as is done in the mountainous regions of California. For major roads risk can be reduced by providing limited access from properties and local roads, grade separated junctions and median dividers between opposite-direction traffic to reduce the likelihood of head-on collisions. The placement of energy attenuation devices (e.g. guardrails, wide grassy areas, sand barrels)
14520-404: The roads of a particular locality, including the quality of the pavement surface , potholes , road markings, and weather . It has been reported that "[p]roblems of transportation participants and road conditions are the main factors that lead to road traffic accidents". It has further been specifically noted that "weather conditions and road conditions are interlinked as weather conditions affect
14652-593: 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. Since 1926, some divided routes were designated to serve related areas, and designate roughly-equivalent splits of routes. For instance, US 11 splits into US 11E (east) and US 11W (west) in Bristol, Virginia , and
14784-417: 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 . In the field, the special route is typically distinguished from
14916-644: The routes rejoin in Knoxville, Tennessee . Occasionally only one of the two routes is suffixed; US 6N in Pennsylvania does not rejoin US ;6 at its west end. AASHTO has been trying to eliminate these since 1934; 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". Special routes —those with
15048-500: 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
15180-406: The section is deemed to comply. Geosynthetics such as geotextiles , geogrids , and geocells are frequently used in the various pavement layers to improve road quality. These materials and methods are used in low-traffic private roadways as well as public roads and highways. Geosynthetics perform four main functions in roads: separation, reinforcement, filtration, and drainage; which increase
15312-437: The slab. The grout can fill small voids beneath the slab and/or sub-base. The grout also displaces free water and helps keep water from saturating and weakening support under the joints and slab edge after stabilization is complete. The three steps for this method after finding the voids are locating and drilling holes, grout injection and post-testing the stabilized slabs. Slab stabilization does not correct depressions, increase
15444-493: The southwest to Oklahoma City , from where it ran west to Los Angeles . Kentucky strongly objected to this designated route, as it had been left off any of the major east–west routes, instead receiving the US ;62 designation. In January 1926, the committee designated this, along with the part of US 52 east of Ashland, Kentucky , as US 60 . They assigned US 62 to the Chicago-Los Angeles route, contingent on
15576-536: The splits in US 11 , US 19 , US 25 , US 31 , US 45 , US 49 , US 73 , and US 99 . For the most part, the U.S. Routes were the primary means of inter-city vehicle travel; the main exceptions were toll roads such as the Pennsylvania Turnpike and parkway routes such as the Merritt Parkway . Many of the first high-speed roads were U.S. Highways:
15708-473: The staff above the number. This will obviate much hard feeling when it is necessary to change a number to the permanently established route. A rare type of special route, known as the Emergency Detour route, is signed with an auxiliary "Emergency" banner that is colored orange, indicating a temporary traffic control sign. The purpose of these routes is to offer an alternative in case the parent route
15840-483: The steer axle and 36,000 pounds (16.329 t) on both of the tandem axle groups is expected to do 7,800 times more damage than a passenger vehicle with 2,000 pounds (0.907 t) on each axle. Potholes on roads are caused by rain damage and vehicle braking or related construction work. Pavements are designed for an expected service life or design life . In some parts of the United Kingdom the standard design life
15972-429: 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 ". As of 1989,
16104-483: The term "bypass" (e.g. U.S. Highway 17 Bypass in Myrtle Beach ). Approaching a population center, it is common for the parent route to split between a business route and a bypass route and rejoin to form the parent on the other side. The American Association of State Highway and Transportation Officials (AASHTO) defines a business route for U.S. highways as ...a route principally within the corporate limits of
16236-548: 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
16368-547: The two routes received the same number, with a directional suffix indicating its relation to the other. These splits were initially shown in the log as—for instance—US 40 North and US 40 South, but were always posted as simply US 40N and US 40S. The most heated argument, however, was the issue of US 60. The Joint Board had assigned that number to the Chicago-Los Angeles route, which ran more north–south than west–east in Illinois, and then angled sharply to
16500-464: The two-digit routes, three-digit routes have been added, removed, extended and shortened; the "parent-child" relationship is not always present. AASHTO guidelines specifically prohibit Interstate Highways and U.S. Routes from sharing a number within the same state. As with other guidelines, exceptions exist across the U.S. Some two-digit numbers have never been applied to any U.S. Route, including 37, 39, 47, 86, and 88. Route numbers are displayed on
16632-477: The unqualified number to the older or shorter route, while the other route uses the same number marked by a standard strip above its shield carrying the word 'Alternate'." Most states adhere to this approach. However, some maintain legacy routes that violate the rules in various ways. Examples can be found in California , Mississippi , Nebraska , Oregon , and Tennessee . In 1952, AASHO permanently recognized
16764-718: Was also chosen, based on the shield found on the Great Seal of the United States . The auto trail associations rejected the elimination of the highway names. Six regional meetings were held to hammer out the details—May 15 for the West , May 27 for the Mississippi Valley , June 3 for the Great Lakes , June 8 for the South , June 15 for the North Atlantic , and June 15 for New England . Representatives of
16896-509: 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. In
17028-521: Was completed in 1923. The American Association of State Highway Officials (AASHO), formed in 1914 to help establish roadway standards, began to plan a system of marked and numbered "interstate highways" at its 1924 meeting. AASHO recommended that the Secretary of Agriculture work with the states to designate these routes. Secretary Howard M. Gore appointed the Joint Board on Interstate Highways , as recommended by AASHO, on March 2, 1925. The Board
17160-418: Was composed of 21 state highway officials and three federal Bureau of Public Roads officials. At the first meeting, on April 20 and 21, the group chose the name "U.S. Highway" as the designation for the routes. They decided that the system would not be limited to the federal-aid network; if the best route did not receive federal funds, it would still be included. The tentative design for the U.S. Route shield
17292-517: Was deferred to a numbering committee "without instructions". After working with states to get their approval, the committee expanded the highway system to 75,800 miles (122,000 km), or 2.6% of total mileage, over 50% more than the plan approved August 4. The skeleton of the numbering plan was suggested on August 27 by Edwin Warley James of the BPR, who matched parity to direction, and laid out
17424-424: Was held August 3 and 4, 1925. At that meeting, discussion was held over the appropriate density of routes. William F. Williams of Massachusetts and Frederick S. Greene of New York favored a system of only major transcontinental highways, while many states recommended a large number of roads of only regional importance. Greene in particular intended New York's system to have four major through routes as an example to
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