U.S. Route 78 (US 78) is an east–west United States highway that runs for 715 miles (1,151 km) from Memphis, Tennessee, to Charleston, South Carolina. From Byhalia, Mississippi to Birmingham, Alabama, US 78 is concurrent with Interstate 22. The highway's western terminus is at U.S. Route 64/U.S. Route 70/U.S. Route 79 (Second Street) in Memphis, Tennessee, and its eastern terminus is on Line Street, in Charleston, South Carolina. One of its related routes, US 278, is actually longer in length than US 78. Route description |- !TN | |- !MS | |- !AL | |- !GA | |- !SC | |-class=sortbottom style="border-top: 2px solid #a2a9b1;" !Total | |} Tennessee 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. Throughout the Tennessee portion, US 78 is overlapped in its entirety by State Route 278 (SR 278), along Linden Avenue and Somerville Street, and State Route 4 (SR 4) along E. H. Crump Boulevard and Lamar Avenue. Mississippi US 78 is a freeway for its entire length in Mississippi. The section from its intersection with Interstate 269 in Byhalia, Mississippi to the Alabama state line is concurrent with Interstate 22. The highway runs across the northeastern rural part of the state, connecting several population centers. Mississippi's portion of US 78 is defined in Mississippi Code Annotated § 65-3-3. The old routing of US 78 through the state is signed as MS 178. Alabama US 78 is a major east–west U.S. highway across the central part of Alabama. It is internally designated State Route 4 (SR 4) by the Alabama Department of Transportation, though the only section of State Route 4 that is signed is along portions mainly west of Jasper. The section from the Mississippi state line to near Graysville is concurrent with Interstate 22; from Graysville south to Birmingham, US 78 takes its original routing. East of Birmingham to the Georgia state line, US 78 has been replaced as a major through-route by Interstate 20. The two routes roughly parallel each other, with junctions at Leeds and Pell City. West of Jasper, old US 78 is signed as AL 118 to Guin, and the segment from Guin northward to I-22 at Hamilton is