Initially, the system was to cover 41,000 miles of road, including 2,000 miles of existing toll roads. It was to be completed in 1975. As time passed it became obvious that goal would not be reached. We came close though; by then the system had about 35,000 miles of roadway.
President Eisenhower, Senator Albert Gore, Sr., Representatives George Fallon and Thomas Boggs, along with Frank Turner, chief of what is now called the Federal Highway Administration, are commonly seen as the fathers of the Interstate system.
There is some disagreement over when the first Interstate was made. Pennsylvania, with its Turnpike, Missouri, with its Interstates 44 and 70 and Kansas with its Interstate 70 all lay claim to being the first. The first three contracts under the new program were signed in Missouri on August 2, 1956. However, all of these roads were either started before the Interstate act was approved, or were upgrades of existing roads. The Pennsylvania Turnpike opened on October 1, 1940 and was the first limited-access, divided highway in the country.
The original name was the "National System of Interstate and Defense Highways." In October 1990, President Bush signed legislation changing it to the Dwight D. Eisenhower System of Interstate and Defense Highways."
In February 1994, the American Society of Civil Engineers declared the Interstate system one of the "Seven Wonders of the United States." Other wonders include the Hoover Dam and the Golden Gate Bridge.
The economic impact of this, the world's largest public works project, is incalculable. There is hardly one aspect of American society that hasn't been affected by the Interstates.
As of December 31, 1995 only 30 miles remain to be built, with 25 of those 30 miles already under construction and the other five in the design phase. When completed, there will be 42,796 miles of Interstates. They represent one percent of the nation's total road mileage yet carry over 20 percent of the nation's traffic.
The longest Interstate is I-90, which runs from Boston to Seattle, a distance of 3,081 miles. At 75 mph it would take you 41 hours to cover that distance non-stop. The second longest is I-80, which covers the 2,907 miles between New York City and San Francisco.
Interstates 5, 10, 15, 20, 25, 35, 40, 70, 75, 80, 90, 94 and 95 are all more than 1,000 miles long.
The shortest Interstate is I-878 in New York City, which is all of seven-tenths of a mile long. That's 3,696 feet.
The highest Interstate route number is I-990 north of Buffalo, NY. The lowest is I-4 across Florida
The only state without any Interstate routes is Alaska.
Interstates carry nearly 60,000 people per route-mile per day, 26 times the amount of all other roads, and 22 times the amount of rail passenger services. Over the past 40 years, that's the equivalent of a trip to the moon for every person in California, New York, Texas, and New Jersey combined.
Over 55,000 bridges had to be built.
There are a total of 58 one- or two-number Interstates in the continental U.S. Of those 58, 27 run primarily east west. The other 31 go primarily north south. There are three Interstates in Hawaii (H-1, H-2, and H-3).
East-west interstate route numbers end in an even number. North-south routes end in an odd number. The basis for this numbering system goes back to the 1920's.
If the first digit of a three-digit interstate route number is odd, it is a spur into a city. If it is even, it goes through or around a city.
1919 Transcontinental Motor Convoy
Woodrow Wilson - Motorist Extraordinaire