The state has about $3.5 billion in federal stimulus and transportation funds from the Obama administration, which would be matched by almost $3 billion from Proposition 1A, a high-speed rail bond approved by California voters in 2008, to build the sections through the central San Joaquin Valley.

Any of the work using stimulus funds, however, must be completed by the fall of 2017.

All of the construction, however, depends on money. In Washington, the Republican-controlled House has stripped any future money for high-speed rail from a transportation funding bill. And, in Sacramento, the rail authority's business plan has been criticized by legislators, analysts and others.

The state Legislature will consider over the next few months whether it will include the Prop. 1A bond money in the state's 2012-13 budget.

"This timeline seems ambitious to me; it looks like a pretty robust timeline," said Lynn Schenk of San Diego, the authority's vice chairwoman, asking van Ark and chief attorney Thomas Fellenz how confident they are with the schedule.

"We need to continue to monitor and stick to this timeline," van Ark said. "We're going to get a contract in place by the end of 2012. That's been what we've promised the board and the people for a long time. ... We cannot give up any moment."

Van Ark added that the contractor teams have told his staff that they believe they can complete the Fresno section within 36 months, by mid-2016, a full year ahead of the stimulus deadline.

But, Fellenz said, "it won't be easy to accomplish."

Prequalified bidders

The five contractor teams that have been prequalified to bid on the project through Fresno are:

California Backbone Builders, a consortium of two Spanish construction firms: Ferrovial Agroman and Acciona.

California High-Speed Rail Partners, composed of Fluor Corp. of Texas, Swedish-based Skanska and PCL Constructors of Canada.

California High-Speed Ventures, made up of Kiewit Corp. of Nebraska, Granite Construction of Watsonville and Comsa EMTE of Spain.

A joint venture of Dragados SA of Spain, Denver-based Flatiron Construction Corp. and Shimmick Construction of Oakland.

Tutor Perini Corp. of Sylmar, Zachry Construction of Texas and Pasadena-based Parsons Corp.