U.S. Route 40 (National Road)

U.S. Route 40 (National Road)
Name	U.S. Route 40 (National Road)
Established	1926 (original National Road legislation 1806)
Length mi	2,385
Direction a	West
Terminus a	San Francisco, California
Direction b	East
Terminus b	Atlantic City, New Jersey
States	California, Nevada, Utah, Colorado, Kansas, Missouri, Illinois, Indiana, Ohio, West Virginia, Pennsylvania, Maryland, New Jersey

U.S. Route 40 (National Road) is a coast-to-coast highway tracing portions of the early 19th-century National Road and later federal highway developments. The route traverses a variety of landscapes and urban centers, linking western termini near San Francisco to eastern termini on the Atlantic Ocean at Atlantic City, while intersecting major corridors and historic communities. It has served as a conduit for commerce, migration, military movements, and cultural exchange across multiple states.

Route description

U.S. Route 40 crosses western urban regions including San Francisco and connects to western corridors like Interstate 80 and Interstate 15, traversing the Sierra Nevada and aligning with rail corridors such as Union Pacific Railroad and Central Pacific Railroad rights-of-way. In the Interior West it links nodes including Salt Lake City, Denver, and Kansas City, interfacing with Interstate 70 and U.S. Route 287, and passing through plains adjacent to Great Plains agricultural zones. Across the Midwest U.S. Route 40 traverses the Missouri River basin, serves metropolitan areas such as St. Louis, Springfield, and Indianapolis, and parallels historic water routes like the Ohio River near Cincinnati. In the Mid-Atlantic the route follows older turnpikes through Baltimore, Philadelphia, and links to port cities such as Newark before reaching Atlantic City. The corridor intersects interstate and U.S. highways including Interstate 95, U.S. Route 1, Interstate 70, Interstate 64, and U.S. Route 66 remnants, and it traverses landscapes characterized by the Appalachian Mountains, the Allegheny Plateau, and the Atlantic Coastal Plain.

History

The roadway incorporates alignments inherited from early federal projects dating to legislation supported by figures like Thomas Jefferson and implemented during the administration of James Madison, evolving from the original National Road project initiated under the aegis of the U.S. Congress and engineers influenced by European precedents such as the Great North Road. Construction milestones involved contractors linked to regions including Cumberland and extended to Vincennes and beyond. In the 19th century the route paralleled stagecoach lines used during partisan events including movements linked to the War of 1812 mobilization and later to westward migration events such as the California Gold Rush. The 20th century brought federal highway numbering reforms under officials associated with the American Association of State Highway Officials and engineering programs inspired by the Good Roads Movement and the New Deal; U.S. Route 40 was designated in 1926, absorbing portions of pre-existing auto trails like the Lincoln Highway and the Victory Highway. During World War II the route accommodated military logistics associated with installations such as Fort Lewis and Fort Knox and postwar suburbanization linked to agencies like the Federal Highway Administration. Preservation debates in the late 20th century involved stakeholders including the National Park Service and local historical societies after impacts from interstate construction projects such as Interstate 70 and urban renewal in cities like Baltimore and St. Louis.

Major intersections and termini

Western termini and major junctions include interchanges with Interstate 80 near San Francisco, crossings of Interstate 15 in Nevada, and connections to U.S. Route 93. Midwestern nodes feature intersections with Interstate 25 proximate to Denver, junctions with Interstate 70 multiple times across Colorado and Kansas, and major urban interchanges in Kansas City with Interstate 35 and Interstate 29. In the Ohio Valley the route meets U.S. Route 52 near Cincinnati, crosses Interstate 71 and Interstate 75, and intersects Interstate 65 at Indianapolis. Eastern termini involve connections with Interstate 95 near Philadelphia and terminus access to coastal arteries in Atlantic City, linking to state routes such as New Jersey Route 42 and New Jersey Route 168. Historic termini originally at Cumberland remain focal points for heritage routes and alignments with roads like U.S. Route 11 and U.S. Route 219.

Historic and cultural significance

The corridor encompasses historic sites including the Cumberland Historic District, structures associated with the National Road era, and roadside architecture reflecting the Automobile Age such as motor courts, diners, and neon signage preserved in towns like Flagstaff, Arizona and St. Louis. Literary figures and artists traveling along the route include associations with Mark Twain, Ernest Hemingway, and photographers like Walker Evans documenting roadside America. Ethnic and migration histories intersect with the route through communities linked to the Great Migration, immigrant neighborhoods in Chicago, and labor movements connected to industrial centers like Pittsburgh. The route features in popular culture through films set along transcontinental highways, performances at venues in Cleveland and Philadelphia, and has been the subject of preservationist works published by institutions such as the Library of Congress and the Smithsonian Institution.

Preservation and highway management

Management responsibilities span state departments including the California Department of Transportation, the Nevada Department of Transportation, the Pennsylvania Department of Transportation, and municipal agencies in cities like Baltimore and Indianapolis. Preservation efforts engage the National Park Service for federally designated segments, the Historic American Engineering Record for documented bridges and alignments, and nonprofit advocates like Route 66 Association-style groups adapted to U.S. Route 40. Funding and policy mechanisms have involved federal programs such as the Interstate Highway System funding legacy, the National Historic Preservation Act, and state transportation improvement plans administered by metropolitan planning organizations like the Metropolitan Transportation Commission (San Francisco Bay Area) and the Ohio-Kentucky-Indiana Regional Council of Governments.

Related routes and alignments

Associated corridors and predecessor alignments include the National Old Trails Road, the Lincoln Highway, and connections with historic U.S. Highways like U.S. Route 66 and U.S. Route 6. Spur and alternate designations have included alignments concurrent with Interstate 70, business routes through municipalities such as Vincennes, and state-numbered continuations including Maryland Route 144 and Pennsylvania Route 40. Scenic byways and commemorative routes that parallel or incorporate parts of the highway encompass designations overseen by entities like the Federal Highway Administration and state historic commissions, while rail parallels include corridors of the Baltimore and Ohio Railroad and the Pennsylvania Railroad.

Category:United States Numbered Highways