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.
Delaware State Route System
U.S. Routes that run north–south have odd numbers, increasing from east to west, while those that run east–west have even numbers, increasing from north to south. Major north–south U.S. Routes have numbers ending in 1 while major east–west U.S. Routes have numbers ending in 0. Three-digit U.S. Routes serve as branches of their parent route. As such, U.S. Route 13 (US 13) runs north–south through the entire length of Delaware while US 40, a major U.S. Route running from Utah to New Jersey, passes east–west through northern New Castle County. US 113 serves as a branch of US 13 in the southern part of the state. US 9 is an exception to the numbering pattern as it runs east–west across Sussex County, though the route runs north–south in New Jersey and New York.