Top officials from the California High-Speed Rail Authority will join some of the rail project's toughest critics in Palo Alto Tuesday afternoon for a public discussion of the controversial, voter-approved rail line.

The public hearing, chaired by Assemblyman Rich Gordon, D-Menlo Park, will focus on the rail authority's newly released business plan, which estimates the cost of the system at $98.6 billion. Gordon chairs a state Assembly budget subcommittee that oversees resources and transportation agencies.

The meeting, which will begin at 1:30 p.m. at City Hall, will feature a panel that includes Roloef van Ark, the chief executive officer of the rail authority, and two recently appointed members of the rail authority's board of directors, Jim Hartnett and Michael Rossi. They will be joined by various supporters of the rail project, including Daniel Krause, executive director of the high-speed-rail advocacy group Californians for High Speed Rail; and Jim Wunderman, president of the Bay Area Council. Cesar Diaz, legislative director of the State Buildings and Construction Trades, will also join the panel.

The panel will also include leading critics of the high-speed rail's ridership models and revenue projections. Elizabeth Alexis, co-founder of the Palo Alto-based watchdog group Californians Advocating Responsible Rail Design, and Samer Madanat, director of the UC Berkeley Institute for Transportation Studies -- both of whom have pointed out flaws in the rail authority's ridership methodology -- will take part in the discussion. William Gridley, whose group Community Coalition on High Speed Rail has reviewed and criticized the rail authority's business model, will also be on the panel, as will Farra Bracht, an analyst at the Legislative Analyst's Office.

William Kempton, chair of the rail authority's peer-review group, will also be on the panel.

The meeting will take place from 1:30 to 4:30 p.m. Tuesday at City Hall, 250 Hamilton Ave. It will be broadcast by the Midpeninsula Community Media Center on Channel 26 and streamed online here.