Interstate Highways are a network of roads in the United States designed for fast and efficient travel across long distances. Established by the Federal-Aid Highway Act of 1956, these highways connect major cities and regions, facilitating commerce and transportation. They are marked with a unique shield symbol and are numbered based on their location and direction. The Interstate system spans over 48,000 miles, making it one of the largest highway systems in the world. These roads are built to high standards, featuring multiple lanes, limited access points, and safety features to accommodate large volumes of traffic.