The shake-up is a setback to the project, not a sign of health, said Quentin Kopp, another former high-speed rail authority board member and state legislator. Van Ark, he said, "was a strong engineer" and Umberg is "highly intelligent and devoted to the project." The loss of Umberg, in particular, is "not a good step," he said.
Beyond vague criticism of Van Ark's political skills, it is not clear what led to his departure, and he has declined to comment.
His resignation announcement came on the day that Parsons Brinkerhoff delivered a technical assessment that disputed one of Van Ark's most significant initiatives: reconsidering the 2005 decision to route the bullet train through Palmdale and the Tehachapi Mountains, rather than up the Grapevine and Interstate 5. After hearing the presentation, the board voted to drop any further consideration of the Grapevine route, even though preliminary indications were that it could be cheaper, shorter and faster than the Palmdale route. A top Parsons Brinkerhoff executive was quoted by Bloomberg News later in the day criticizing Van Ark's tenure.
Under Van Ark, the authority unveiled a business plan in early November that was considered one of the last chances for the authority to produce a credible blueprint for building and financing the massive $98.5-billion project.
But not long after the plan's release, outside experts, transportation researchers, government officials and activists attacked the document, asserting that it was unrealistic and unaffordable. A number of state and local lawmakers began echoing the criticism, egged on by public opinion polls that showed a majority of the state's voters no longer supports the project.
ralph.vartabedian@latimes.com
dan.weikel@latimes.com