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.
List of road interchanges in the United States
Some of the biggest ones are: Kennedy Interchange (I-64/I-65/I-71) in Louisville, Kentucky; the Marquette Interchange (I-94/I-43/I-794) and the $1.8 billion Zoo Interchange both in Milwaukee, Wisconsin; the Pregerson Interchange (I-110/I-105) in Los Angeles; and the Circle Interchange (I-90/I-94/I-290) in Chicago.