completion of I-565, the SR 20 designation was removed from all remaining portions of the former route east of I-65. History When the Interstate Highway System was first laid out during the mid-1950s, I-65 was routed on a north–south bee line connecting Nashville, Tennessee, with Birmingham, Alabama. This route passes just to the east of Decatur, which was a major river port on the Tennessee River at the time. Huntsville, however, was still a small town about east of I-65. During the late 1950s and through the 1960s, Huntsville underwent massive population growth due to the establishment of the US Army Missile Command at Redstone Arsenal and the new NASA Marshall Space Flight Center. By 1960, Huntsville had grown to be more than twice the size of Decatur. It became clear that an Interstate Highway spur route would be beneficial to connect Huntsville with I-65 and to the rest of the country. I-565 was chosen as the Federal Highway Administration (FHWA)'s number for this proposed spur expressway. It was decided that, rather than terminating at the western edge of Huntsville, I-565 would extend farther eastward, providing an east–west freeway for Huntsville. On the eastern edge of Huntsville, I-565 was designed to feed into US 72, which was being widened to a four-lane highway traveling from Huntsville to Kimball, Tennessee, where it feeds into I-24. Construction of I-565 began in 1987, and the freeway was opened on October 26, 1991. By the time construction had begun, Huntsville had become one of the most populous cities in the contiguous United States without a freeway connection to the Interstate system. Construction was performed in phases. Phase 1 opened in 1989 and extended from the east side of Mooresville to County Line Road (exit 7, which was originally constructed to serve as a terminus taking traffic between I-565 and SR 20). At the time, traffic from I-65 still had to drive through Mooresville to where the Interstate started while the Mooresville overpasses and bridges over creeks were constructed. Phase 2 added a bypass through Madison. The Interstate still ended at County Line Road, requiring traffic to take SR 20 through Madison until about Slaughter Road where a temporary entrance/exit merged traffic back onto I-565. The route then traveled along the old Governors Drive path past the Space and Rocket Center until it terminated with two lanes exiting at what is now the Governors Drive