[The group] approved a plan for the often congested corridor with core elements that call for expansion of the highway in certain locations as well as construction of an "advanced guideway" train by 2025. . . .
[The plan includes] widening I-70 to a total of six lanes from Floyd Hill through the Twin Tunnels just east of Idaho Springs, making major improvements to the I-70/U.S. 40 interchange near Empire and adding climbing and acceleration/deceleration lanes on I-70 between the Bakerville exit and the Eisenhower/Johnson Tunnel. . . .
"[T]riggers" that would allow additional expansion of I-70 and other transit improvements beyond the advanced-guideway concept.
One trigger would occur when initially identified highway improvements are complete and an advanced guideway train is operating "from the Front Range beyond the Continental Divide," . . . Another authorizes the second phase of expansion, and other transit options, if studies on the feasibility, cost, ridership and other issues related to the advanced-guideway train show it is deemed technically "unfeasible" or "cannot be funded" by 2025.
One such study, a year-long, $1.5 million analysis of high-speed rail possibilities for the I-70 and Interstate 25 corridors, is just getting underway.
The I-70 corridor, which is perennially clogged by ski resort traffic, in season, is currently served by Amtrak, but it is slow and secured only a small percentage of all traffic despite reasonably good public transit and reasonably walkable communities upon arrival at the resorts.
The trip from Union Station in downtown Denver to Vail Resorts, is about 97 miles by road. On a good day, this is an hour and a half journey. But few Friday nights and Saturday mornings on westbound I-70, and few Sunday nights on eastbound I-70, in ski season, are good days. In heavy traffic, the trip takes several hours.
The report doesn't discuss the option, but earlier proposals also included HOV lanes. Some type of contraflow system would make a great deal of sense for the corridor, as it typically jams up in only one direction at a time, even without highway expansion.
One would expect construction costs for both the highway expansion and rail portions of the project to be much higher than average, given the mountainous terrain and possibly expensive condemnation of mountain homes which might be required. Indeed, the hope that rail could be reduce the amount of expensive highway expansion needed otherwise, and might be possible to build with less of a footprint, is one of the important reasons to seriously consider it.
A high speed passenger rail line in the I-25 corridor ought to be far cheaper to build, has no current Amtrak rail service, and would also probably have higher traffic as it would link multiple cities. If through freight rail traffic could be diverted to a route further out on a front range, a proposal seriously being considered at this time, the passenger rail system could even be build in existing right of ways, possibly with only modest modifications of existing track.