Planning for the Denver-Boulder Turnpike began in 1927 with Professor Roderick L. Downing, whose University engineering students later surveyed its route and who pressed for its construction for more than 20 years while also contributing to highway planning in Colorado. Many others also worked to make the road a reality, including the Highway Committee of the Boulder Chamber of Commerce, which began advocating for it in 1941, and a Boulder-Denver direct route committee formed after World War II that overcame obstacles and doubts about toll financing. Bonds totaling $6.3 million were authorized in July 1950, and the highway opened in January 1952 as the Denver-Boulder Turnpike, the first highway of its kind in Colorado and earlier than the similar Interstate Highways. Its bond debt was repaid 13 years ahead of schedule, and the route became a free public highway in September 1967.