Guided busway system among several transit ideas for I-70 |

Guided busway system among several transit ideas for I-70

SILVERTHORNE – The future of Interstate 70’s mountain corridor could include six lanes of highway from Denver to Silverthorne, several new tunnels and additional mountain bores, accompanied by a mass transit guideway system.

Or not.

Colorado Department of Transportation representatives say no one yet knows just what changes will be made to improve the flow of traffic through the mountains, though the six-lane-with-mass-transit idea was one of several possibilities outlined during an all-day meeting on the problem held at Silverthorne’s Four Points Sheraton Wednesday. Planners are narrowing down the list of possible solutions, a process that has been years in the making already.

The preferred option likely will include a mix of highway improvements and some mass transit. But all those possibilities are being considered as part of the state highway department’s Programmatic Environmental Impact Statement (PEIS), and Wednesday’s meeting – which drew more than 100 people from ski areas, truckers associations, towns up and down the I-70 corridor and CDOT – gave those stakeholders an update on the study’s progress.

A video simulation showed what I-70 would be like if it were six-laned from Floyd Hill west of Denver to Idaho Springs. (Tentative proposed plans call for six lanes from Floyd Hill to Silverthorne, but the simulation did not show the entire corridor.) That simulation showed portions of the eastbound highway elevated through Clear Creek County, where the interstate footprint is narrow and options for widening it are limited.

Other ideas: a third bore at the twin tunnels west of Idaho Springs and a tunnel for eastbound traffic at the base of Floyd Hill – both with the idea of improving safety and allowing for faster travel time by eliminating some of existing curves. CDOT engineers also propose a third bore at the Eisenhower Tunnel.

Additionally, headway is still being made on plans to add some form of mass transit to the corridor – in the form of a monorail-style fixed guideway or perhaps as a diesel/electric bus guideway system. While the monorail has gotten a fair amount of scrutiny and publicity in the past, Wednesday’s meeting put significant focus on the bus guideway system.

That idea calls for building a track, which can fit into a fairly narrow footprint, specifically for the buses. Buses can drive off an arterial road onto the guideway, then accelerate up to 80 mph on a fixed system that requires minimal guidance from the driver. At various points along the guideway, and at the end of the line, the bus can roll off the guideway and merge back into regular traffic.

The cost for all these improvements? Anywhere from $300 million for a plan CDOT labels “minimal action” to as much as $9.4 billion for changes that incorporate a combination of highway widening and mass transit.

A timeline has not been set for making any improvements, nor has a method of financing been decided, state highway representatives said. But CDOT officials expect to have a list of recommended changes in hand by early 2004 and a final decision on what must be done in 2005. At that point, CDOT will need to find a way to pay for the improvements and begin the work.

That’s cold comfort to skiers and summer mountain vacationers who too often find themselves idling in bumper-to-bumper traffic on Sunday afternoons, but CDOT’s Cecilia Joy, project manager for the PEIS, asked the public to be patient.

“These changes will have permanent effects,” she said. “These are our mountains. We all care very much about them. There’s no doubt this is a long-term proposal, and to make a wise decision takes time.”

Jane Reuter can be reached at (970) 668-3998, ext. 229, or by e-mail at

Meeting Time

The next meeting, which will focus on costs and technical aspects of alternatives for alleviating traffic on I-70, is planned for 9:30 a.m. to 4 p.m. April 30 at the Four Point Sheraton in Silverthorne. For more information on the PEIS, go to

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