By definition an interstate highway should go between two or more states. However, there are several highways in the United States which were built as part of the Eisenhower system which are actually intrastates meaning that they only go between cities in one state and never cross borders. Examples include:
- H1, H2, and H3 which all service the island of Oahu, Hawaii
- I45 which goes between Dallas and Galveston in Texas
- I27 which goes between Amarillo and Lubbock in Texas
- I49 which goes between Shreveport and Lafayette in Louisiana
- I12 which goes between Baton Rouge and Slidell in Louisiana
- I17 which goes between Flagstaff and Phoenix in Arizona
- I19 which goes between Tucson and Nogales in Arizona
- I4 which goes between Daytona and Tampa in Florida
- I16 which goes between Macon and Savannah in Georgia
Please note that I am not including three digit "beltways" such as I495 Long Island Expressway in New York.
| 
