DENVER -- Transportation officials say a rail system is not an option to help ease congestion in and out of the mountains but they have narrowed down the final possibilities. One option is a guided bus system that would run in the median, essentially from the Eisenhower tunnel to C-470.

A second plan would add traffic lanes in Dowd Canyon as well as from the tunnel to Floyd Hill.

So why not a rail system from Denver to Vail? Transportation officials say it would cost too much. The Colorado Department of Transportation said yhe monorail carried a price tag of $5.6 billion and the price of a traditional rail line was pegged at $4.4 billion. But in contrast, the price of the preferred highway expansion or bus guideway proposals range from $1.7 billion to $2.9 billion.

Public officials and residents of Clear Creek County, where much of the new pavement would be placed, say they will be left with the higher pollution and land lost to roadbeds.

"I'm very disappointed, but not terribly surprised. We had a suspicion they were favoring asphalt," said Idaho Springs Mayor Dennis Lunbery. Public comment on the plans will begin early next year.

As part of an ongoing environmental review, CDOT and the Federal Highway Administration on Tuesday released their preferred alternatives.

All proposals include the construction of new tunnel bores at the Eisenhower Tunnel and the Twin Tunnels just east of Idaho Springs.

Clear Creek County commissioner Jo Ann Sorensen said the highway expansion would decimate the county's communities.

"Why go to six lanes that in 20 years will be more congested than they are today?" Commissioner Harry Dale added.

Funding for any of the work also remains to be determined, officials said.