List of Interstate Highways
There are 70 primary Interstate Highways in the Interstate Highway System, a network of controlled-access freeways in the United States. They are assigned one- or two-digit route numbers, whereas their associated "auxiliary" Interstate Highways receive three-digit route numbers. Typically, odd-numbered Interstates run south-north, with lower numbers in the west and higher numbers in the east; even-numbered Interstates run west-east, with lower numbers in the south and higher numbers in the north. Highways whose route numbers are divisible by "5" usually represent major coast-to-coast or border-to-border routes (ex. I-10 travels from Santa Monica, California, to Jacksonville, Florida, traveling from the Pacific to Atlantic oceans). Additionally, auxiliary highways have their numbering system where a different number prefixes the number of its parent highway.
Transportation in Minnesota
The interstate highways are part of a class of routes known as interregional corridors, which also includes U.S. Routes 2, 8, 10, 14, 52, 53, 61, 63, 169, and 212 and Minnesota State Highways 23, 34, 36, 60, 210, and 371. Interregional corridors represent two percent of the state's highways but account for one-third of all vehicle miles traveled. Less heavily traveled regional corridors include U.S. Routes 12, 59, 71, and 75, and a number of state highways.