SACRAMENTO (AP) — The board overseeing California's plan to build a $98 billion high-speed rail system chose an appointee of Gov. Jerry Brown on Thursday to take over as its chairman.

The Democratic governor appointed Dan Richard to the California High-Speed Rail Authority board last year to help turn around a project that has come under intense criticism for its cost, ridership and route plans.

Estimated costs have more than doubled since voters approved selling bonds for it in 2008. In addition, the statewide system is expected to be completed in 2033, 13 years later than originally estimated.

Brown has maintained his support despite criticism of the project.

"The fundamentals of high-speed rail, the reasons why California should embark on high-speed rail, are sound," Richard told the board and about people who attended a hearing in Sacramento. "Having said that, we also know that our business plan probably can be improved in a number of ways. ... As we revise our plans, I think people will see that we've been responsive to the public concerns."

Richard is a former member of the Bay Area Rapid Transit District. He replaces Tom Umberg, who stepped down as chairman last month but remains on the board.

The board also will begin the search for a new chief executive officer to replace Roelof van Ark, who announced his resignation in January.