Instruct: Given a question, retrieve passages that answer the question.
Query: What is the longest highway in the U.S.?
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.
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).
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.
Highway 13 (AR 13, Ark. 13 and Hwy. 13) is a designation for three state highways in the central part of the U.S. state of Arkansas. The longest segment of travels from U.S. Route 79 (US 79) in Humphrey to Campground Road east of Beebe. There exists two short segments in White County; one traveling from Highway 367 in McRae to Highway 36 in Searcy and the other traveling from Highway 367 in Judsonia to Highway 258.
U.S. Route 6 travels east–west near the north edge of the U.S. state of Pennsylvania from the Ohio state line near Pymatuning Reservoir east to the Mid-Delaware Bridge over the Delaware River into Port Jervis, New York. It is the longest highway segment in the Commonwealth. Most of it is a two-lane rural highway, with some freeway bypasses around larger towns. Except east of Dunmore, where it is paralleled by Interstate 84, it is the main route in its corridor. What is now Interstate 80—the Keystone Shortway—was once planned along the US 6 corridor as a western extension of I-84. The corridor was originally the Roosevelt Highway from Erie, Pennsylvania to Port Jervis, New York, designated Pennsylvania Route 7 in 1924. The PA 7 designation soon disappeared, but as US 6 was extended and relocated, the Roosevelt Highway followed it. The Pennsylvania section of US 6 was renamed the Grand Army of the Republic Highway in 1946; this name was applied to its full transcontinental length by 1953.
North of Hampton, Minnesota, U.S. Highway 55 headed north and west to downtown Minneapolis. Within the village of Hampton, Minnesota, U.S. Highway 55 followed along Main Street and present-day Minnesota Highway 50 to Farmington. Within Farmington, the highway had a shared segment with what was then U.S. Highway 65 (now Minnesota Highway 3) to Elm Street in Hampton.
They are home to the longest high school football rivalry in Texas: the Battle of the Ax, against Sherman High School.Denison is served by two U.S. Highways—U.S. 69 and U.S. 75 (North Central Expressway) and two State Highways—State Highway 91 and Spur 503 (Eisenhower Parkway). State Highway 91, known as Texoma Parkway, is one of the main commercial strips that connects Sherman and Denison. It also extends north to Lake Texoma.
U.S. Route 9 (US 9) is a part of the U.S. Highway System that runs from Laurel, Delaware, to Champlain, New York. In New York, US 9 extends from the George Washington Bridge in Manhattan to an interchange with Interstate 87 (I-87) just south of the Canada–United States border in the town of Champlain. US 9 is the longest north–south U.S. Highway in New York; additionally, the portion of US 9 in New York accounts for more than half of the highway's total length.
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 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 in length. The longest route is U.S. Route 67, which runs from Texarkana to Missouri.
State Highway 18, abbreviated as SH-18 or OK-18, is a highway maintained by the U.S. state of Oklahoma. It was once one of the longest state highways in the Oklahoma road system, but now has a total length of .
Highway 355 is a north–south highway in southwest Arkansas. The southern terminus of its longest section is at an intersection with U.S. Route 67 in Fulton. Its northern terminus is at an intersection with U.S. Route 278 south of Center Point. Communities along this route include Fulton, McNab, Saratoga, Tollette, and Mineral Springs.
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.
The following is a list of U.S. Highways in Maryland. There are currently 14 U.S. Highways that exist entirely or partially in the U.S. state of Maryland. Seven of these are primary U.S. Highways while seven are auxiliary U.S. Highways that may or may not be related to one of the primary U.S. Highways. The longest primary U.S. Highway in Maryland is U.S. Route 40 (commonly abbreviated US 40) at . The shortest primary U.S. Highway in Maryland is US 11 at . The longest auxiliary U.S. Highway in Maryland is US 301 at . The shortest auxiliary U.S. Highway in Maryland is US 522 at . All U.S. Highways are maintained by the Maryland State Highway Administration except for the portions that run through Baltimore, Hagerstown, and Cumberland. Maryland has five former U.S. Highways; those five are shaded in dark gray in the list.
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.
U.S. Route 30 (US 30) is an east–west main route of the system of United States Numbered Highways, with the highway traveling across the northern tier of the country. It is the third longest U.S. route, after U.S. Route 20 and U.S. Route 6. The western end of the highway is at Astoria, Oregon; the eastern end is in Atlantic City, New Jersey. Despite long stretches of parallel and concurrent Interstate Highways, it has not been decommissioned unlike other long haul routes such as U.S. Route 66.
Maryland has 14 U.S. Highways, including seven primary U.S. Highways and seven auxiliary U.S. highways. The longest U.S. highway in Maryland is U.S. Route 40, while the shortest U.S. highway is US 522. Maryland also contains six former U.S. highways.
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.
The US Highways in Nebraska are the segments of the national United States Numbered Highway System that are owned and maintained by the U.S. State of Nebraska totaling . The longest of these routes is U.S. Route 30 at around . On a national level, the standards and numbering for the system are handled by the American Association of State Highway and Transportation Officials (AASHTO), while the Nebraska Department of Transportation is responsible for their maintenance. Route numbers are not reused between the various highway systems within the state. For example, Interstate 80 is the only route in Nebraska with the number 80.
The primary highway system makes up over , a mere 8 percent of the U.S. state of Iowa's public road system. The Iowa Department of Transportation is responsible for the day-to-day maintenance of the primary highway system, which consists of Interstate Highways, United States Highways, and Iowa state highways. Currently, the longest primary highway is U.S. Route 30 at . The shortest highway is Interstate 129 at .
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. 
The U.S. Highways in Utah are painted by the Utah Department of Transportation (UDOT). The United States Numbered Highway System is a nationwide system with only a small portion of its routes entering Utah. Originally, the State Road Commission of Utah, created on March 23, 1909 was responsible for maintenance, but these duties were rolled into the new UDOT in 1975. There are of U.S. Highways in the state. The longest is U.S. Route 89 at and the shortest is U.S. Route 89A at . Five former U.S. Highways exist in the state of Utah, all of which have been replaced by current interstate and U.S. Highways, with the most recent change being U.S. Route 666 redesignated as U.S. Route 491 in 2003.
U.S. Route 76 (US 76) is an east–west U.S. highway in the U.S. state of South Carolina. Being one of the longest highways in the state, it connects the cities of Anderson, Columbia, Sumter and Florence.
In the United States, each state maintains its own system of state highways. This is a list of the longest state highways in each state. , the longest state highway in the nation is Montana Highway 200, which is long. The shortest of the longest state highways is District of Columbia Route 295, which is only long.
The U.S. Highways in Alabama are the subset of the United States numbered highway system. These highways in the U.S. state of Alabama are maintained by the Alabama Department of Transportation (ALDOT). There are 19 U.S. highways that travels through Alabama, totaling . U.S. Route 31 (US 31) is the highway with the longest segment in Alabama, with . The shortest is US 72 Alternate, crossing of North Alabama. One former U.S. highway existed in Alabama: US 241. It traveled through the eastern part of the state. US 241 was replaced by US 280 and US 431 in 1954.