Interstate 40 in Tennessee.
In Tennessee, Interstate 40 (I-40) runs from west to east, from the Mississippi River at the Arkansas border to the Blue Ridge Mountains at the North Carolina state line. Paralleling the older U.S. Route 70 corridor, I-40 passes through Tennessee's three largest cities—Memphis, Nashville, and Knoxville—and serves the Great Smoky Mountains National Park, the most-visited national park in the United States. At 455.28 miles (732.70 km), the Tennessee segment of I-40 is the longest of those in the eight states through which the highway passes and the state's longest Interstate Highway. Built in segments, I-40 in Tennessee was mostly complete by the late 1960s. The construction of the highway resulted in the U.S. Supreme Court decision Citizens to Preserve Overton Park v. Volpe (1971), increasing the scope for judicial review of administrative actions. The case caused the state to realign I-40's route through Memphis onto what was originally a section of I-240.
