In 1970, I-79 swapped positions with I-279, necessitating that I-76 be extended to I-79. With commencement on the Beaver Valley Expressway in 1971, PA 60 was extended to its future northern terminus in Chippewa. Finally, on October 2, 1972, after I-76 west of Monroeville moved to the Pennsylvania Turnpike and replaced I-80S, the western part of the highway took the I-279 designation while the section from Pittsburgh east to Monroeville would become the first section with the I-376 designation. When I-376 was extended onto the Parkway West in 2009, I-279 was truncated to its current southern terminus at the former western terminus of I-376.