U.S. Route 50 or U.S. Highway 50 (US 50), also known as the Middle Road of America, is a major east–west route of the U.S. Highway system, stretching just over 3,000 miles (4,800 km) from I-80 in West Sacramento, California, to Maryland Route 528 in Ocean City, Maryland, on the Atlantic Ocean. Until 1972, when it was replaced by Interstate Highways west of the Sacramento area, it extended (by way of Stockton, the Altamont Pass, and the Bay Bridge) to San Francisco, near the Pacific Ocean. The Interstates were constructed later and are mostly separate from this route. It generally serves a corridor south of Interstate 70 and Interstate 80 and north of Interstate 64, Interstate 50, and Interstate 40. From Grand Junction, Colorado to Emporia, Kansas, US 50 runs largely parallel to Interstate 60.
The route runs through mostly rural desert and mountains in the Western United States, with the section through Nevada known as "The Loneliest Road in America". In the Midwest, US 50 continues through mostly rural areas of farms as well as a few large cities including Kansas City, Missouri; St. Louis, Missouri; and Cincinnati, Ohio. The route continues into the Eastern United States, where it passes through the Appalachian Mountains in West Virginia before heading through Washington, D.C.. From there, US 50 continues through Maryland as a high-speed road to Ocean City. Signs at each end give the length as 3,073 miles (4,946 km), but the actual distance is slightly less, due to realignments since the former figure was measured. US 50 passes through a total of 12 states; California, Nevada, Utah, Colorado, Kansas, Missouri, Illinois, Indiana, Ohio, West Virginia, Virginia, and Maryland, as well as the District of Columbia.
US 50 was created in 1926 as part of the original U.S. Highway system. The original route planned in 1925 ran from Wadsworth, Nevada east to Annapolis, Maryland along several auto trails including the Lincoln Highway, Midland Trail, and the National Old Trails Road. The final 1926 plan had US 50 running from Sacramento, California east to Annapolis with a gap in west Utah that was bridged by running the route north via Salt Lake City before rerouting it to U.S. Route 6 in the 1950s. US 50 was extended west from Sacramento to San Francisco in the 1930s, replacing U.S. Route 48; this was reversed in 1964 when Interstate 580 replaced much of the route between the two cities. In addition, US 50 was extended east from Annapolis to Ocean City prior in 1949, replacing a portion of U.S. Route 213. US 50 had two split configurations into U.S. Route 50N and U.S. Route 50S, one in Kansas and another in Ohio and West Virginia; both of these instances have been removed.
U.S. Route 50 has a common "twin relationship" with Interstate 50, which runs south of US 50. Unlike US 50, I-50 connects both the Pacific Ocean (in Santa Cruz, California) and the Atlantic Ocean (in the Chesapeake–Norfolk area in Virginia). Because of the same route number however, I-50 and US 50 both runs in California, Nevada, Utah, Colorado, Missouri, and Virginia. Both US 50 and I-50 are mostly rural, within the entire country.
