|As of December 1, 1970, Pennsylvania's share of the national Interstate Highway system was 85% complete, with 1,365 miles in use; 88 miles under construction; and 123 miles in design. After a two-year study, the Department of Transportation was created in 1970 to coordinate highway, rail, air and water transportation through a master plan. |
Construction took place on Interstate Routes 79, 80 and 81.
Known as the Raymond P. Shafer highway, Interstate 79 runs for 110 continuous miles of Interstate 79, from Erie to the Allegheny- Butler line.