Instruct: Given a question, retrieve relevant passages that answer the question.
Query: What is the longest USA highway?
U.S. Highway 20 (US20) is an east–west United States highway that stretches from the Pacific Northwest all the way to New England. The "0" in its route number indicates that US20 is a coast-to-coast route. Spanning 3,365 miles (5,415km), it is the longest road in the United States,[1] and particularly from Newport, Oregon to Boston, Massachusetts, the route is roughly parallel to that of the newer Interstate 90 (I-90), which is in turn the longest Interstate Highway in the U.S. There is a discontinuity in the official designation of US20 through Yellowstone National Park, with unnumbered roads used to traverse the park.
Highway 97 is the longest continuously numbered route in the Canadian province of British Columbia (and the longest provincial highway in any province), running from the Canada–United States border near Osoyoos in the south to the British Columbia/Yukon boundary in the north at Watson Lake, Yukon. The route takes its number from U.S. Route 97, with which it connects at the international border. The highway was initially designated '97' in 1953.
BR-116 is a federal highway of Brazil. One of the most important highways in Brazil and the second longest, its connect Fortaleza, Ceará, one of the largest Northeast Brazil metropolises, to the southern city of Jaguarão, Rio Grande do Sul, in the border with Uruguay. It is also the longest highway in the country to be completely paved.
Highway 400 is the second longest freeway in the province, the trans-provincial Highway 401 being the longest. It was the first fully controlled-access highway in Ontario when it was opened between North York and Barrie on July 1, 1952. On that date, it was also the first highway to be designated as a 400-series. The freeway was extended in both directions; north of Barrie to Coldwater in 1958, and south of Highway 401 to Jane Street in 1966. It was widened between North York and Barrie in the 1970s. Since 1977, construction on the freeway has been snaking north along Highway 69 towards Parry Sound and Sudbury.
Certain older parts of Plainfield have suffered from extreme traffic congestion. Before Interstate 55 was built just east of the town in the late 1950s, U.S. Route 30, The Lincoln Highway and U.S. Route 66 (sometimes referred to as "The Mother Road") merged into one street for three blocks on what is now Illinois Route 59. This merge is now only shared by U.S. 30 and Lincoln Highway, between Plainfield/Joliet Road on the south to Lockport Street on the north, but continues to be an area of heavy traffic congestion even outside heavy commuting periods. At one time, the two longest paved highways in the world (Lincoln Highway and U.S. Route 66) crossed within Plainfield. The highways only crossed each other twice and both locations are in Will County. The other location is in neighboring Joliet.
U.S. Route 20 is the longest numbered highway in the entire country and also holds the distinction of being the longest numbered highway in the state, edging out Route 28 by merely a mile (Route 28 is long).
Highway 363 is a highway in the Canadian province of Saskatchewan. It runs from Highway 4 to Highway 2 in Moose Jaw. Highway 363 is about long, and is the longest of the 300 series highways within the province.
The Anton Anderson Memorial Tunnel, often called the Whittier Tunnel after the town at its eastern terminus, is a dual-use highway and railroad tunnel that passes under Maynard Mountain. At a length of , it is the second-longest highway tunnel and longest combined rail and highway tunnel in North America. The tunnel was upgraded to mixed use by the Kiewit Construction Company.
Highway passes through valley of South Morava, passes west of Niš, by Merošina and Leskovac, and after Grdelica built highway ends. 26 kilometers of highway under construction passes through Grdelica gorge, very difficult terrain. This sections is often considered the hardest one to build in Serbia. On this part of highway will be 33 bridges, of which Vrla bridge will be longest (around 650 meters long and around 60 high), and two tunnels: "Predejane" (1000 m) and "Manajle" (1818 m) which will be the longest tunnel in Serbia. Near Vladičin Han highways leaves Grdelica gorge and there is beginning of Vladičin Han - Donji Neradovac section. Highway passes by Vranje, and near Bujanovac constructed section ends. Last 8 kilometers of highway under construction passes by Bujanovac and in Levosoje starts last 21 kilometers of A1 highway. Few kilometers south of Preševo is Border Crossing Preševo with FYR Macedonia.
The highway is the longest single highway in the country, though it is shorter than the combined totals of the two highways that comprise State Highway 1, SHs 1N and 1S.
The A1 is the country's longest and only toll highway connecting the port city of Durrës on the Adriatic Sea in the west as well as the capital of Tirana in the center, with the country of Kosovo in the northeast. The A3 is the second longest motorway and connects Tirana with the Pan-European Corridor VIII, running from Durrës on the Adriatic Sea to Varna on the Black Sea. The A2 is the third longest motorway and represent a significant north-south corridor within the country and the Adriatic-Ionian motorway.
Unlike most Interstate Highways, much of I-70 in Utah was not constructed parallel to or on top of an existing U.S. Highway. Portions of I-70 were constructed in areas where previously there were no paved roads. Because it was built over an entirely new route, I-70 has many features that are unique in the Interstate Highway System. For example, the between Green River and Salina makes up the longest distance anywhere in the Interstate Highway System with no motorist services. This same piece is noted as the longest highway in the United States built over a completely new route since the Alaska Highway, and the longest piece of Interstate Highway to open at a given time. The construction of the Utah portion of I-70 is listed as one of the engineering marvels of the Interstate Highway System.
The Interstate Highway System covers about in the state and consists of four primary highways and nine auxiliary highways. There are additional 29 business routes associated with the system in Michigan. The longest segment of Interstate Highway in the state is Interstate 75 (I-75) at just under ; the shortest is I-375 at . The length of I-75, the longest highway of any kind in the state, includes the Mackinac Bridge, which is maintained by the MBA, the only section of state highway not under MDOT jurisdiction. The Mackinac Bridge is one of three monumental bridges in the state used by I-75; the others are the Zilwaukee and International bridges. A fourth, the privately owned Ambassador Bridge connects I-75 and I-96 in Detroit to Canada.
State Highway 16, or SH 16, is a south–north state highway that runs from Zapata on the Texas-Mexico boundary to U.S. Highway 281 24 miles (38.6 km) south of Wichita Falls. It is the longest state highway in Texas at almost 542 miles, but is only the 9th longest of any highway classification in the state. Before the 1939 renumbering, SH 4 was the longest state highway. 
Two interesting facts about highway 40 are: The segment from roughly Hinton to Grande Prairie is part of the shortest fully paved land route from the USA to the Klondike Gold fields in the Yukon, and if the segments of the Forestry Trunk Road and Highway 40 were connected, the total length would be approximately and it would be the second longest highway in Alberta.
Despite what its name may suggest, the speed limit on the highway is less than that of an expressway. The highway also has a traffic light junction at its intersection with Clementi Road, something that expressways do not have. The at-grade section of the highway is a three-lane dual carriageway, and the viaduct is a two-lane dual carriageway with a 1-metre hard shoulder. At a length of 5 km, the viaduct is the longest in Singapore.
Prior to the construction of I-70, the swell was inaccessible via paved roads and relatively undiscovered. Once this section was opened to traffic in 1970, it became the longest stretch of interstate highway with no services and the first highway in the U.S. built over a completely new route since the Alaska Highway. It also became the longest piece of interstate highway to be opened at one time.
Although opened in 1970, this section was not formally complete until 1990, when a second steel arch bridge spanning Eagle Canyon was opened to traffic.
At just over , SR 11 is the longest state highway in Maine, and the second longest numbered highway in the entire state (behind US 1, which runs just over in Maine). It is almost longer than Maine's longest Interstate Highway, its section of Interstate 95 (I-95). Overall, Route 11 in Maine, New Hampshire, and Vermont are long.
Interstate 95 (I-95) is a part of the Interstate Highway System that parallels the East Coast of the United States from Houlton, Maine in the north to Miami, Florida in the south. In the U.S. state of Massachusetts, it spans along a south–north axis. It is the third-longest Interstate Highway in Massachusetts, behind I-90 (the Massachusetts Turnpike) and I-495, while I-95 in full is the longest north–south interstate, and sixth-longest Interstate Highway in the United States.
Eyre Highway begins at the town of Norseman, on the Coolgardie–Esperance Highway. Apart from Eucla, from the South Australia border, roadhouses serving the highway are the only settlements on the stretch through Western Australia. These are located apart, at Balladonia, Caiguna, Cocklebiddy, Madura, and Mundrabilla. The section between Balladonia and Caiguna includes what is regarded as the longest straight stretch of road in Australia and one of the longest in the world. The road stretches for without turning, and is signposted and commonly known as the "90 Mile Straight". Travelling east, the highway descends through the Madura Pass just before the Madura roadhouse from the Nullarbor Plain to the coastal Roe Plains. It skirts the bottom of the escarpment, climbing back through the Eucla Pass just before Eucla.
Because of its remoteness, some widened sections of the highway serve as emergency airstrips for the Royal Flying Doctor Service. These airstrips are signposted, have runway pavement markings painted on the road, and turnaround bays for small aircraft.
Highway 18 is a highway in the Canadian province of Saskatchewan. It runs from Highway 13 near Robsart, approximately east of the Alberta border, to the Manitoba border near Gainsborough, where it becomes Highway 3. It passes through three major communities, all in the eastern quarter of Saskatchewan – Estevan, Oxbow, and Carnduff; it also passes north of the west and east blocks of Grasslands National Park. Highway 18 is about long, which is the longest east-west highway and second longest highway in Saskatchewan.
Vermont Route 100 (VT 100) is a north–south state highway in Vermont in the United States. Running through the center of the state, it travels nearly the entire length of Vermont and is long. VT 100 is the state's longest state highway, the longest north-south route in Vermont, and the longest numbered highway in Vermont of any type.
It is located at 1 Yonge Street at Queens Quay, and marks the foot of what was Highway 11, known informally as "the longest street in the world".
Puerto Rico Highway 149 (PR-149) is a secondary highway in Puerto Rico that connects the towns of Manatí in the north coast of Puerto Rico, from PR-22 to Juana Díaz in the south coast, ending at PR-1. It goes through Ciales, and is a divided highway and a wide rural highway between that municipality and Manatí, as it is also from Juana Díaz to Villalba. From Ciales to Villalba is an extremely dangerous mountain road, with very high areas and poor safety barriers. From Ciales to Villalba it passes through the Salto de Doña Juana, a spot with a small waterfall and a small creek where people can jump and swim. It is one of the longest highways going south to north, perhaps the longest excluding PR-1 and PR-52.
U.S. Route 6 (US 6), also called the Grand Army of the Republic Highway, honoring the American Civil War veterans association, is a main route of the U.S. Highway system. While it currently runs east-northeast from Bishop, California to Provincetown, Massachusetts, the route has been modified several times. The highway's longest-lasting routing, from 1936 to 1964, had its western terminus at Long Beach, California. During this time, US 6 was the longest highway in the country.