History Timeline
- 1909: The first highway bill was passed by forming a three-member Highway Commission to approve work and allocate funds. The Commission first took their post on January 1, 1910.
- 1917: The State Highway Fund was created and a State Highway Department (CDOH - Colorado Department of Highways) was formed.
- 1935: Highway Department employees were joined by 44 new co-workers selected from among 7,500 applicants to become the first members of the Colorado State Highway Courtesy Patrol. The Patrol became a division of the Highway Department.
- 1947: The first National System of Interstate and Defense Highways was approved by the federal works administrator. In Colorado, approved routes included all of I-25 from the Wyoming border to Raton Pass; all of I-80S (now I-76); and I-70 from Denver to the Kansas border.
- 1953: The state legislature passed a new law reorganizing the Highway Department and renaming it the Colorado Department of Highways.
- 1956: Congress passed the Federal Interstate Highways Act. Among the approvals was the section of I-70 from Denver to the Utah border.
- 1991: CDOH became Colorado Department of Transportation (CDOT)
- 2010: CDOT celebrates its 100-year anniversary
Fun Facts
- Interstate first signed and showed up on Colorado maps in 1961.
- Highest point on Interstate system is at the Eisenhower Tunnel. – 11,155 feet. Also, it’s the highest vehicular tunnel in the United States.
- The last section of interstate highway to open in Colorado was I-76 between Pecos Street and I-25, in September 1993. Completion of this segment marked the completion of the interstate system in Colorado.
- Colorado has 956 designated miles of interstate highway
- The I-70 Final Link segment in Glenwood Canyon was dedicated in October, 1992. That completed the mainline interstate system (excluding connector interstates) in the U.S. This 12.5 mile segment includes 40 bridges and viaducts, three tunnels, 15 miles of retaining wall, four full-service rest areas and a bikepath.
- Colorado's interstate highway system comprises 10% of the total state highway system, yet 40% of the 43.5 billion miles of Colorado vehicle travel annually take place on the interstate system
- The first segment of freeway in Colorado, later to become I-25 when the federal law creating the interstate highway system was passed in 1956, was a 2 mile segment of the Valley Highway in Denver, which began construction in August, 1948, and was completed in 1950. The entire segment of Valley Highway north-south through the Denver metro area was completed in 1958.
- A 9.2 mile segment of freeway in Pueblo, later also to become a segment of I-25, began construction in 1949 on the right of way of U.S. Hwys. 85/87 and was completed in 1958
- The first Colorado link of interstate highway with another state occurred on Oct. 11,1964, when a 26-mile segment of I-25 from Wellington, CO, to the Wyoming state line, was completed and opened.
- The first bore of a major highway tunnel through the continental divide on what is today's I-70 began in 1968. Completed in 1973, this was the current westbound bore of I-70, named the Eisenhower Memorial Tunnel. Its contract, for $54.14 million, was the larges single federal aid highway contract ever awarded in the United States up until that time.
- It took the new Eisenhower Tunnel only four months to carry its one-millionth vehicle; three months later, it carried its two-millionth vehicle
100 Years of Colorado State Transportation History
