Interstate 79 (I-79) is an Interstate Highway in the Eastern United States, designated from I-77 in Charleston, West Virginia, north to Pennsylvania Route 5 (PA 5) and PA 290 in Erie, Pennsylvania. It is a primary thoroughfare through western Pennsylvania and West Virginia and makes up part of an important corridor to Buffalo, New York, and the Canada–United States border. Major metropolitan areas connected by I-79 include Charleston and Morgantown in West Virginia and Greater Pittsburgh and Erie in Pennsylvania.

Interstate 77 (I-77) is a north–south Interstate Highway in the Eastern United States. It traverses diverse terrain, from the mountainous state of West Virginia to the rolling farmlands of North Carolina and Ohio. It largely supplants the old U.S. Route 21 (US 21) between Cleveland, Ohio, and Columbia, South Carolina, as an important north–south corridor through the middle Appalachian Mountains. The southern terminus of I-77 is in Cayce, South Carolina, in Lexington County at the junction with I-26. The northern terminus is in Cleveland at the junction with I-90. Other major cities that I-77 connects to include Columbia, South Carolina; Charlotte, North Carolina; Charleston, West Virginia; and Akron, Ohio. The East River Mountain Tunnel, connecting Virginia and West Virginia, is one of only two instances in the U.S. where a mountain road tunnel crosses a state line. The other is the Cumberland Gap Tunnel, connecting Tennessee and Kentucky. I-77 is a snowbird route to the Southern U.S. for those traveling from the Great Lakes region.