Interstate Highway is a term used to refer to a network of controlled-access highways that are federally funded and operated by the U.S. Department of Transportation's Federal Highway Administration. The term SYST is an abbreviation for the system of Interstate Highways, which is a network of highways that span the entire United States. The system was created in 1956 with the passage of the Federal-Aid Highway Act, and it has since grown to include over 47, 000 miles of roadway. The system is designed to provide a safe and efficient means of transportation for both passenger and commercial vehicles.