The state's high-speed train battle makes a pivotal stop in Silicon Valley on Tuesday night, with hundreds of residents expected to join key Democratic legislators, independent analysts and project officials to vet the plan.

Dan Richard, who Gov. Jerry Brown appointed to chair the California High-Speed Rail Authority board, is expected to provide details on the $100 billion bullet train's final business plan. Though no one will say what Richard will disclose at the hearing, the new plan -- due to be unveiled in the next three weeks -- will detail the rail line's updated cost, funding plan, construction timeline and other key estimates.

Three Senate Democrats who have been skeptical of the railroad are hosting the informational hearing in Mountain View. When state officials vote this June on whether to launch the project, Democratic legislators stand as the swing vote between the supportive governor and Republican opponents.

"This hearing will give residents of the Peninsula and South Bay a sneak peek at the High-Speed Rail Authority's latest thinking before the final plan is released, and provide a local opportunity for comment and input to help shape that final plan," said Sen. Joe Simitian, D-Palo Alto, who is hosting the hearing. He'll be joined by Sen. Alan Lowenthal, D-Long Beach, who chairs the senate's high-speed rail committee, and Sen. Mark DeSaulnier, D-Concord, who chairs the transportation committee.

With the bullet train issue galvanizing the region -- the tracks will run along the current Caltrain corridor -- officials booked the 600-seat Center for the Performing Arts at 500 Castro St. to host the meeting, which starts at 7 p.m.

After testimony by Richard, who would be joined by Jim Hartnett, the Peninsula's representative on the rail board, representatives from two independent groups that have issued stinging rebukes of the project -- the Legislative Analyst's Office and Will Kempton, chair of the High-Speed Rail Peer Review Group -- will then testify.

Residents will then get a rare local opportunity to let their voices be heard in person by project officials, a prospect that is expected to carry the hearing into the wee hours of Wednesday morning.

Though the railroad has been met with much skepticism, more than 100 labor leaders and other advocates will hold a rally beforehand, holding signs touting the benefits of the rail line as attendees file in.

Contact Mike Rosenberg at 408-920-5705.