To add approximately 500 miles to the National System of Interstate and Defense Highways for construction of an interstate route to connect Memphis, Tennessee with Huntsville, Alabama and with Chattanooga, Tennessee, and Atlanta, Georgia, and for other purposes.

Authorizes additional mileage for construction of an interstate route to connect interstate route I-40 in Memphis, Tennessee, with Huntsville, Alabama, and with route I-24 near Chattanooga, Tennessee, and I-75 between Chattanooga, Tennessee, and Atlanta, Georgia.

Amends the Federal-Aid Highway Act of 1956 to authorize the use of funds under such Act for construction of such interstate route.