The Sierra Club and Utahns for Better Transportation unveiled a new transportation plan Wednesday that emphasizes mass transit and shuns the Legacy Parkway.

But the citizen groups said they recognize a need for more roadways in the booming Davis County. The groups are proposing that UDOT build a road that extends Redwood Road from I-215 and heads north to Parrish Lane at I-15, giving Utahns a second corridor to get from Davis County to Salt Lake.

"The fast choice is we can build more highways and sit in traffic," said Bob Adler, a law professor at the University of Utah. "The real choice is we can build more highways, promote a baby Los Angeles and still sit in traffic. Or we can have a smarter transportation program that preserves Utah and still provides Utahns with the transportation services that they need.

The citizen groups' comments came on the same day Utah Department of Transportation officials made the rounds to local media outlets in advance of Friday's expected release of the Legacy Parkway supplemental environmental impact statement (SEIS).

UDOT executive director John Njord told the Deseret Morning News editorial board the estimated cost of the project has risen to at least $570 million, more than $100 million above the previous cost estimate.

Njord said the increase is due to a rise in the cost of materials, the three-year delay of the project imposed by the courts, and the expectation that bidding contractors will be less likely to give the department a good price due to the risks associated with a project that could again be challenged in court.

UDOT remains optimistic it can begin construction of the 14-mile southern Davis County highway as soon as spring 2006 and complete it by late 2008 or early 2009.

The Sierra Club and Utahns for Better Transportation say they can provide Davis County commuters with a better alternative for $200 million less. Dubbed "The Smart Growth Initiative," the new proposal will emphasize light rail, bus rapid transit and commuter rail.

Once Davis County residents get used to the idea of mass transit, the road connecting I-215 and I-15 through Redwood Road would be built.

"UDOT wants to build a new highway first, we want to build transit first," Adler said. "We want to provide more roadway capacity, but data has shown around the county, around the world and here in Salt Lake County that if you build transit first that people will try it out and make it part of their lifestyle."

The Smart Growth Initiative will also widen I-15 to 10 lanes through parts of Davis County.