Their main gripe, Richard said, was that high-speed rail, unlike other transportation projects, lacked a guaranteed revenue source such as a gas tax.

"What has happened in the last few weeks is that the governor's office and the Department of Finance have basically structured it so that high-speed rail will be able to make application for cap-and-trade revenues, should we need it," he said.

Richard and a fellow authority board member, Michael Rossi, said the agency still will seek federal funds over the coming decade to build the Merced-Burbank section, even though the Republican-controlled Congress has denied the Obama administration's requests for future money for high-speed rail projects.

"We're hoping to get a federal commitment over the next 10 years of at least $4 billion, and we're going to do everything we can to develop private-sector revenues from station development, right-of-way leasing and advertising," Richard said. "If that doesn't close the gap, we've got the cap-and-trade funds as a backstop."

The revised business plan predicts that in 2022, the first year of operations with paying passengers between Merced and Burbank, high-speed trains would provide 2.9 million to 5 million rides. Even with the most pessimistic estimate, Rossi said, more than enough tickets would be sold to cover the cost of operations and maintenance without any state subsidy. The break-even point, he added, is about 2.3 million riders.

"We feel good that we've addressed a lot of the public concerns" from the Nov. 1 version of the business plan, Richard said. "It's not like there aren't still going to be challenges and even uncertainties, but we feel this is a very reasonable and workable path forward for the state."

Not everyone is likely to be convinced, however.

State Sen. Doug LaMalfa, R-Willows, had not seen the updated business plan, but said he remains concerned about how the system will be paid for. "Where does the rest of the money come from?" asked LaMalfa, who is spearheading an effort to repeal Prop. 1A.

He also has doubts that the proposal lives up to what voters approved in 2008.

Voters believed that "it would be a true high-speed rail from one end to another and that it has to operate on its own, that the state can't be underwriting it," LaMalfa said. "This is far short."

Richard said the authority's latest plan does cost more than the $43 billion anticipated in 2008 but does what the law requires. "With this blended system, we can get from Los Angeles Union Station to the Transbay Terminal in 2 hours 40 minutes, hitting speeds of 220 mph and operating that system without a subsidy, precisely as is commanded by Prop. 1A," he said. "And we don't need to build anything else in order to achieve that."

Authority board members said the new plan provides benefits for the San Joaquin Valley even before high-speed trains begin rolling. Federal funding strings require work on the Fresno-Bakersfield stretch to be completed by fall 2017. Richard said the authority will work with Caltrans to improve existing freight tracks used by Amtrak's San Joaquin trains.