What is the importance of America's interstate highways?

Today, two million trucks travel the interstates and move more than 10 billion tons of goods across the United States. It is possible for them to drive more than 2,400 miles (4,000 kilometers) from the East Coast to the West Coast, or more than 1,200 miles (2,000 kilometers) from the Canadian border to the Mexican border—all thanks to the interstate (“between states”) highways. People in passenger cars can also drive these distances, making it possible for them to travel easily and quickly from one part of the country to another. The highways, which have no traffic signals or stop signs, cross more than 55,000 bridges and can be found in 49 of America’s 50 states. (Only Alaska has no interstate highways, although Hawaii’s “interstate” highways don’t cross state lines either). The Interstate Highway system is usually two roads, one in each direction, separated by an area that is planted with grass and trees. Each road holds two lines of cars that can travel at speeds between 65 and 75 miles per hour (104 to 120 kilometers per hour).The Interstate Highway system—signed into law in 1956 by President Dwight Eisenhower—set off a highway-building boom that produced nearly 47,000 miles (75,639 kilometers) of interstate highways as of 2004. It has been an important part of the nation’s economic growth since the 1950s, as trucks using the system carry about 75 percent of all products that are sold in the country. Jobs and new businesses have been created near the busy interstate highways, including hotels, motels, diners and fast-food restaurants, gas stations, and shopping centers. At the end of the twentieth century, the U.S. government renamed the Interstate Highway system to the Eisenhower Interstate System.