CDOT issued two draft reports on Wednesday that state the 340-mile high-speed transit system would cost an estimated $30 billion.
A high-speed transit line from Denver International Airport to ski country in Eagle County would cost $16.5 billion. A line connecting Fort Collins to Colorado Springs through Denver would total $13.6 billion.
The agency says building the system in phases would create significant financing challenges.
CDOT spoke with members of the private financial community and concludes only about $1-3 billion could be obtained in private financing for the project. The rest would need to come from local, state and federal funding.
"It's clear that we currently lack the financial capacity to build either of these projects," Mark Imhoff, CDOT's Division of Transit and Rail director, said in a statement. "However, the studies show that a statewide system could provide many benefits to the businesses, individuals and tourists that depend on our interstates."
CDOT says the population along the Front Range is projected to increase from 4 million to 6 million by 2040. Population in the I-70 Mountain Corridor is expected to reach 400,000, twice as much as today.
The studies predict the high-speed system could serve 18-19 million passengers a year by 2035. That would be 4-6 million in the mountain corridor and 12-14 million on the Front Range corridor.
CDOT says the system would include travel speeds of 90 to 180 miles per hour, saving one-fourth to two-thirds of the time it now takes to drive. Some projected travel times:
- C470/I-70 in Golden to Breckenridge would take just over a half hour.
- C470/I-70 to Vail would take 50 minutes.
- Fort Collins to DIA would take less than 40 minutes.
- Colorado Springs to DIA would take less than an hour.