The San Joaquin rail line, operated by Caltrans' Division of Rail, is the fifth-busiest Amtrak corridor in the U.S., with more than 1 million riders last year. On the Burlington Northern Santa Fe freight tracks, Amtrak trains now run at an average speed of 50 mph, Richard said, and a top speed of 79 mph.

Improvements such as train controls and more protected road crossings north of Merced would boost the top speed of Amtrak trains to 90 mph. And by shifting onto the new high-speed tracks between Merced and Bakersfield -- as an interim measure while construction takes place over the Tehachapi range -- the San Joaquin trains could run at up to 125 mph.

The plan is sure to come under intense scrutiny from legislators who are being asked this year to approve money from Proposition 1A, a $9 billion bond measure approved by California voters in 2008.

About $2.7 billion in Prop. 1A funds is required to qualify for $3.3 billion in federal stimulus and transportation money to build the Fresno-Bakersfield portion of the line.

Critics -- including the state's legislative analyst, a Prop. 1A expert review group and other officials, and some lawmakers in Sacramento -- were shocked by the high cost from the November plan and have been skeptical that high-speed trains can operate without subsidies from taxpayers.

Rossi, the authority board member and a former executive with Bank of America, said he has repeatedly analyzed potential ridership, revenue and expenses over the past six months. He said Monday that even if costs are 30% higher than being projected now, and revenues 30% lower, "there is no need for a subsidy."

Another key concern of critics has been where the authority will find money to build anything more than the Fresno-Bakersfield portion for which the Obama administration has earmarked the $3.3 billion. The Republican-controlled Congress has pledged to block any future money for high-speed rail in federal budgets.

The new plan identifies cap-and-trade money raised from the sale of air-pollution credits as a dedicated source of state money that can serve as a backstop if no future federal funds come through.

Gov. Jerry Brown's proposed 2012-13 state budget indicates that cap-and-trade credits could generate as much as $1 billion in revenue next year.

Authority board members, however, say they will continue to pursue more federal money if and when it comes available. And President Barack Obama has not given up on trying to come up with that money, said Karen Hedlund, deputy administrator with the Federal Railroad Administration.

"The president's 2013 budget requests $2.5 billion for rail development projects and establishes the first of a six-year strategy to invest $47 billion in our nation's rail system," she said at the event Monday.

Authority members believe their plan answers many questions, but other critics say their concerns have yet to be addressed.

Valley farmers remain worried about how much acreage the high-speed right-of-way will consume and how the tracks themselves might disrupt farming or dairy operations in the region.

Richard will meet this afternoon in Hanford with the Kings County Board of Supervisors, who still harbor considerable resentment toward the authority over the proposed route through their county and its effects on farms. Supervisors say their requests for cooperation from the authority have been ignored.

Kings County Supervisor Richard Valle attended Monday's news conference, but said he could not relate to the revised business plan "because Kings County wasn't a part of that process."

"The voices of Kings County, the questions that came from Kings County residents, have not been answered," he said. "It's the same old statement."

Maureen Fukuda of Hanford said rural areas like Kings County have different priorities. "This event was all about Fresno, connecting Fresno," she said. "Farmers don't need to be connected."

In Merced, which will initially be the northern terminus once high-speed trains start running, officials said the revised plan makes sense.

Lee Boese, who co-chairs the Greater Merced High-Speed Rail Committee, said his group had been concerned about the project cost getting close to $100 billion. "Seeing that come back with a lower cost and a new route, it was really great to see," Boese said.

Former Merced Mayor Bill Spriggs said building high-speed rail is less expensive than building freeway lanes and airport gates.

"Bottom line, we've got to figure out how to efficiently move people in California," he said. High-speed rail "works well, it gets people moved."