On April 16, 1963, due in part to the extension of I-79 south from the Pittsburgh area, Pennsylvania proposed a partial renumbering. A new number, tentatively designated I-76, would run from Downtown Pittsburgh east on what was then I-70 (I-70S bypassed Pittsburgh to the south on what is now I-70) to the Pennsylvania Turnpike at Monroeville, and then east along the remainder of I-80S to I-295. I-80S would remain on the section of turnpikes from west of Youngstown to Monroeville. This was approved February 26, 1964, and included the renumbering of all X80 spurs to X76.