A map of the Interstate Highways in the contiguous United States (not including Hawaii).

The Interstate Highway System — The Federal-Aid Highway Act of 1956 created 40000 miles of high-speed roads and changed the American landscape. It carries nearly one quarter of the nation’s highway traffic.

President Eisenhower was right when he said the Interstate System would “change the face of America.”

The official name of the Interstate System is the Dwight D. Eisenhower National System of Interstate and Defense Highways. The Interstates would be essential to national defense. It was built to eliminate unsafe roads, inefficient routes, traffic jams and all of the other things that got in the way of “speedy, safe transcontinental travel.” The road network would permit quick emergency evacuation of large areas. Details… (video 1:51)

Just the facts

  • Although the Interstate System accounts for about 1.1 percent of the Nation’s total public road mileage, it carries 24 percent of all highway travel.
  • Chicago can be called the Interstate Crossroad because more long-distance Interstates pass through the city than any other—I-55, I-57, I-88, I-90 and I-94. Four cities are tied for second with four—Indianapolis, Baltimore, Cleveland, Dallas-Fort Worth, and New York.
  • How many times does the Interstate System cross the Mississippi River? 20. How many Interstates cross the Mississippi River more than once? One (I-55 at Memphis, Tennessee and St. Louis, Missouri.
  • more…


  • construction
  • limited access
  • clover-leaf
  • truck stops

What’s the problem?
How to build and Interstate

Do It
Challenges for you to work on…

  • Things You Can Do – Fun activities that you can do in your everyday life to learn more about Interstates.

Learn more…