Interstate Highways are owned and maintained by INDOT unless it is a toll road. The Indiana Department of Transportation (INDOT) is responsible for the establishment and classification of a state highway network which includes interstate highways, U.S. highways, and state roads. ... Image File history File links US_blank. ... Image File history File links I-blank. ... The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly called the Interstate Highway System, is a network of highways (also called expressways) in the United States. ... The Indiana Department of Transportation is the agency of the state of Indiana charged with maintaining and regulating transportation and transportation related infrastructure such as state owned airports, state highways and state owned canals or railroads, as well as state routes, US highways and Interstates that lie within the state. ...