U.S. Route 45

U.S. Route 45 is a major north–south United States Numbered Highway running from Mobile, Alabama to Ontonagon, Michigan. Established in 1926 during the creation of the United States Numbered Highway System, the route connects Gulf Coast port facilities and inland manufacturing centers, traversing metropolitan areas such as Birmingham, Alabama, Jackson, Mississippi, Memphis, Tennessee, Paducah, Kentucky, Paducah (note: duplicate), Chicago, Illinois, and Milwaukee, Wisconsin. The highway intersects with multiple transcontinental corridors including Interstate 65, Interstate 20, Interstate 55, Interstate 64, Interstate 57, and Interstate 90.

Route description

The southern terminus at the Port of Mobile, Alabama ties into infrastructure used by Alabama State Port Authority, Maritime Administration, United States Army Corps of Engineers, and freight carriers that access the Gulf Coast shipping lanes. Through Alabama, the route passes near Birmingham–Shuttlesworth International Airport, the University of Alabama at Birmingham, and industrial zones served by CSX Transportation and Norfolk Southern Railway. In Mississippi, the highway provides arterial access to Jackson, where it intersects corridors to Mississippi State University, Vicksburg, and historic sites like Natchez Trace Parkway. Entering Tennessee, the alignment serves the Memphis metropolitan area, crossing near Graceland and interchanges with routes to Shelby Farms and the Memphis International Airport. In Kentucky, the route connects to river ports on the Ohio River near Paducah and cultural sites such as the Paducah Floodwall Murals and proximity to Land Between the Lakes National Recreation Area. The Illinois segment includes rural stretches between Cairo, Illinois and Metropolis, Illinois before advancing into the Chicago metropolitan area, where it interfaces with rail hubs like Chicago Union Station and landmarks such as Grant Park. In Wisconsin, the highway moves through Milwaukee, adjacent to Lake Michigan, major employers including Harley-Davidson, and onward into the Upper Peninsula of Michigan, terminating near Porcupine Mountains Wilderness State Park and communities connected to Keweenaw National Historical Park.

History

Allocated in the 1926 plan by the American Association of State Highway Officials, the route was influenced by industrial growth driven by entities such as U.S. Steel, Standard Oil, and regional port authorities. Early paving projects were funded via programs involving the Federal Aid Road Act of 1916 and later the Federal-Aid Highway Act of 1956, which also established the Interstate Highway System that reshaped long-haul traffic patterns along the corridor. During the Great Depression, New Deal agencies including the Works Progress Administration and the Civilian Conservation Corps performed labor on segments near Jackson, Mississippi and Chicago, Illinois. World War II logistics elevated the corridor's importance for movements to facilities like Camp Shelby and Naval Air Station Meridian. Postwar suburbanization around Memphis, Tennessee and Milwaukee, Wisconsin prompted widening projects funded by state departments such as the Alabama Department of Transportation, Mississippi Department of Transportation, and Illinois Department of Transportation. Historic alignments were altered by river engineering projects coordinated with the U.S. Army Corps of Engineers and by urban renewal programs overseen by the Department of Housing and Urban Development.

Major intersections

The highway intersects numerous federal and state corridors, creating strategic nodes: - Southern terminus near U.S. Route 98 and access to Interstate 10 in Mobile, Alabama; connections to Alabama State Route 13 and local arterial networks. - Interchanges with Interstate 65 at Birmingham, Alabama area approaches; proximity to U.S. Route 31 and U.S. Route 82. - Crossings with Interstate 20 and Interstate 59 around Jackson, Mississippi; links to U.S. Route 80 and U.S. Route 49. - In Memphis, Tennessee, junctions with Interstate 40, Interstate 55, and Interstate 240 near Beale Street and Downtown Memphis. - Ohio River crossings and connectors to Interstate 24 and Interstate 57 in the Paducah and Southern Illinois region; access to U.S. Route 60. - In Chicago, Illinois, major interchanges with Interstate 90, Interstate 94, and Interstate 290 near the Loop and industrial corridors feeding Chicago River terminals. - Northern segment meets Interstate 43 and Interstate 94 in Milwaukee, Wisconsin; final junctions with Michigan state highways near Ontonagon, Michigan and regional routes serving Houghton, Michigan and Ironwood, Michigan.

Auxiliary routes

Several related numbered routes and business alignments provide local access and bypass functions: - Business routes in Aberdeen, Mississippi, Carthage, Tennessee and other municipalities, coordinated with American Association of State Highway and Transportation Officials standards. - Spurs and connectors to ports and industrial parks managed in cooperation with Port Authority of New York and New Jersey-style state authorities and regional development agencies in Alabama and Illinois. - Former alternate routings created to serve downtown cores in Chicago, Illinois and Memphis, Tennessee later redesignated as state or municipal roads under agencies like Wisconsin Department of Transportation.

Future plans and improvements

Planned upgrades involve widening, safety improvements, and interchange reconstructions funded by state legislatures and federal programs including the Infrastructure Investment and Jobs Act. Projects under consideration engage stakeholders such as the Federal Highway Administration, regional planning organizations like Metropolitan Planning Organization (MPO)s in Memphis and Chicago, and freight interests including BNSF Railway and UPS. Environmental reviews reference the National Environmental Policy Act for impacts near ecologically sensitive areas such as the Desoto National Forest and Great Lakes watersheds. Corridor resiliency efforts coordinate with Federal Emergency Management Agency initiatives for flood mitigation along the Mississippi River and Lake Michigan shorelines. Planned multimodal integration includes improved access to intermodal terminals serving Amtrak routes and connections to Greyhound Lines hubs.

Category:United States Numbered Highways