State Route 4 (Tennessee)

U.S. Route 78
Route information
Length:	715 mi (1,151 km)
Existed:	1926 – present
Major junctions
West end:	US 64 / US 70 / US 79 at Memphis, TN
	I-240 at Memphis, TN I-22 near Byhalia, MS I‑20 / I‑59 at Birmingham, AL I‑65 at Birmingham, AL I‑75 / I‑85 at Atlanta, GA I‑20 near Thomson, GA I‑520 at Augusta, GA I-95 at St. George, SC I-26 at North Charleston, SC I-526 at North Charleston, SC
East end:	Line Street at Charleston, SC
Location
States:	Tennessee, Mississippi, Alabama, Georgia, South Carolina
Highway system
United States Numbered Highway System List Special Divided Replaced

U.S. Highway 78 is an east–west United States highway that runs for 715 miles (1,151 km) from Memphis, Tennessee, to Charleston, South Carolina. A segment of US 78 from near Memphis, Tennessee, to Birmingham, Alabama, is designated as Interstate 22.

The highway's western terminus is at U.S. Route 70 (Second Street) in Memphis, Tennessee. Its eastern terminus is on Line Street, in Charleston, South Carolina.

US-78 runs along Linden Avenue, Somerville Street, E. H. Crump Boulevard, and Lamar Avenue through Memphis, Tennessee. In Tennessee, US-78 is historically known as Pigeon Roost Road, and some aborted sections of the highway in Mississippi also claim that name as well as Lamar Avenue.

US 78 is completely a freeway from the Tennessee state line to Graysville, Alabama. It is now designated Interstate 22 from its intersection with the Memphis Outer Beltway in Byhalia, Mississippi to Graysville where it diverges from I-22. At the time the highway was reconstructed to freeway standards, conversion to an interstate was not considered likely. As a result, Tennessee has never upgraded its portion from the state line to Interstate 240. Mississippi's portion of U.S. 78 is defined in Mississippi Code Annotated § 65-3-3.

US-78 is a major east–west state highway across the central part of Alabama. It is internally designated "State Route 4" (SR-4) by the Alabama Department of Transportation. Due to the construction of Interstate 22 along the US-78 corridor west of Birmingham, part of US-78 is temporarily State Route 5 only, since that part of the new I-22/US-78/SR-4 is not completed. US-78 roughly parallels Interstate 20 from Birmingham east to the Georgia state line.

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Wikipedia