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Kansas celebrates 50 years of Interstates


I-70 - the First Open Interstate

The first segment of Interstate highway completed in the United States was a segment of I-70 that opened west of Topeka on November 14, 1956. The segment followed US-40. The event marked the beginning of the largest public works project in modern U.S. history.

The general route of I-70 was laid out during the early months after the Federal-Aid Highway Act was enacted in 1956. It incorporates a portion of the Kansas Turnpike from Kansas City to Topeka, which opened in October 1956.

When the entire 424-mile stretch of I-70 in Kansas was finished in June 1970, it was the longest continuous segment of Interstate highway to be completed by any state. At the time, Kansas, Missouri, and Pennsylvania were the only states to have a multi-lane I-70 from border to border. It originally cost $155.6 million (an average of $420,000 per mile) to construct the 370 miles of I-70, not including the Kansas Turnpike portion.

Portland cement concrete was used on I-70 from Salina east to Topeka and in Kansas City, and asphaltic concrete (asphalt) pavement was used from Salina west to the Colorado border.

Visit the page below to learn more about this historic event.

"First in the Nation" (reprint from 1956 KDOT newsletter)