Interstate 80
I-80 is the Interstate Highway that most closely approximates the route of the historic Lincoln Highway, the first road across the United States. The highway roughly traces other historically significant travel routes in the Western United States: the Oregon Trail across Wyoming and Nebraska, the California Trail across most of Nevada and California, the first transcontinental airmail route, and except in the Great Salt Lake area, the entire route of the First Transcontinental Railroad. From near Chicago east to near Youngstown, Ohio, I-80 is a toll road, containing the majority of both the Indiana Toll Road and the Ohio Turnpike. I-80 runs concurrently with I-90 from near Portage, Indiana, to Elyria, Ohio. In Pennsylvania, I-80 is known as the Keystone Shortway, a non-tolled freeway that crosses rural north-central portions of the state on the way to New Jersey and New York City.
Interstate 73
Interstate 73 (I-73) is an Interstate Highway, located within the U.S. state of North Carolina. It is part of a longer planned corridor, defined by various federal laws to run from Myrtle Beach, South Carolina, to Sault Ste. Marie, Michigan, but only the part south of West Virginia is under study as of 2012. The corridor passes through the states of South Carolina, North Carolina, Virginia, West Virginia, Ohio, and Michigan. Ohio and Michigan do not plan to build any part of the highway, as the I-73 corridor in both of these states is already served by existing freeways or 4-lane highways that will eventually be upgraded to freeways. West Virginia is building its section, mostly along U.S. Highway 52, as a four-lane divided highway, but not meeting the Interstate Highway standards. On the other hand, North Carolina and South Carolina have built sections and Virginia plans to build its part. Thus Interstate 73 will, once scheduled projects are completed, run from South Carolina to Roanoke, Virginia, where it will end at Interstate 81. Associated with these plans are those for the extension of Interstate 74 from Cincinnati to Myrtle Beach, with several highway overlaps contemplated.