Utah County received an early Christmas present Wednesday — plans for 24 miles of good road, 10 rebuilt or refurbished freeway interchanges and 55 rebuilt or restored bridges.

The Utah Department of Transportation announced that the Utah County I-15 corridor expansion will extend from Lehi's Main Street to Spanish Fork's Main Street, adding two lanes in both directions to the existing freeway, and the project will be completed two years earlier than planned.

Construction will begin in the spring and should be completed by December 2012.

Provo River Constructors, a consortium of contractors and engineers, beat out two other groups for the $1.7 billion project in a fixed-price, best-design bidding process that resulted in a deal for the state, according to project director Dal Hawks.

"All along, we felt confident that we could afford to build a project from American Fork to the Provo Center Street interchange," Hawks said. "These proposals really did what we hoped. All three did an excellent job. We think we picked a contractor who proved the very best possible value for the state."

Hawks said the Provo River proposal is driver friendly, fast and will deliver a superior road surface.

For one thing, Provo River plans to keep existing freeway lanes open throughout the construction process, easing fears that the project could create massive traffic jams.

"They made some very good strategies for maintaining traffic flow," Hawks said.

For another, the consortium will use concrete pavement designed to last 40 years.

"This project is quality throughout," said Heather Barnum, the corridor expansion project's spokeswoman. "This is above the 20-year or 30-year product that we had expected. It will improve the state's investment."

Barnum said the economic downturn worked for the stateby creating a favorable bidding environment.

"We asked the bidders to tell us what they could give us within the budget given by the Legislature," she said. "They came back with more than we supposed we could get."

The project is designed to meet travel demands on the 24-mile stretch through 2030.

The Provo River consortium is headed by Fluor Corp., Ames Construction, Ralph L. Wadsworth Construction and Wadsworth Brothers Construction.

Other companies bidding on the project included one led by Kiewit Western and one led by Flatiron Constructors, Skanska USA and Zachry Construction.

Highlights of the project include:

Two additional travel lanes in both directions from Lehi's Main Street to U.S. 6, and one additional lane from U.S. 6 to 6800 South in Spanish Fork.

An extension of the express lane from University Parkway in Orem to Spanish Fork in both directions.

A rebuild of seven freeway interchanges, with modifications to another three, and the replacement or widening of 55 aging bridges, including the Sam White's Lane Bridge near American Fork, which was torn down after it was hit by a truck in November 2008.

A pedestrian overpass to Utah Valley University across University Parkway in Orem.

Provo's Center Street interchange will remain open during construction.

e-mail: [email protected]