But the 125-mph trains still could zip along on an aerial viaduct, in an underground tunnel, through an open trench or at street level, according to a report released Thursday by the California High-Speed Rail Authority.
The Authority's "preliminary alternatives analysis" identifies ways that the 48 miles of tracks between San Jose and San Francisco could be configured. It also eliminates options it deemed unfeasible due to factors such as geology, various cities' regulations, negative effects on traffic, the need to protect natural resources and more.
The overall rail line, which would stretch from Los Angeles to San Francisco, received voters' approval for $9.95 billion in funding in November 2008.
Since then, rancorous debate and considerable grass-roots activism, along with city-organized lawsuits and lobbying, has ensued. Opponents, some protesting the rail line altogether and others advocating for a plan that will not harm residents' quality of life, have questioned the state agency's processes, calculations and receptivity to public input.
But holding fast to its prior plans, the Authority states that its analysis "reconfirms that a four-track, grade-separated, shared Caltrain and High-Speed Train system is feasible and the preferred … alternative between San Francisco and San Jose on the Peninsula."
Furthermore, it asserted the costs for building the system are consistent with prior estimates, including those found in the 2009 Business Plan, which was released in December.
The agency did state that it has heeded community wishes, however, which have been vocally expressed over the past year and a half. The report promises that berms — solid walls that would extend at least 10 feet into the air — will be sparsely used in commercial or residential areas "where they would significantly reduce connectivity and mobility or where there is strong local opposition to this type of structure."
The agency removed high berms from consideration altogether from Redwood City to San Jose, although shorter berms may be used to connect aerial and underground or at-grade portions.
The report confirmed that tunneling — a method advocated by Palo Alto officials as early as 2008 — has been added "for further evaluation."
Using underground tunnels is only one of six options the Authority is studying. The other five include berms; aerial viaducts, which are concrete structures supported by columns, usually 10 feet or taller; at-grade tracks that run at or near ground level; open trenches, which are below-ground-level troughs; and covered trenches/tunnels, which are partly covered troughs that allow ground-level roads or buildings to exist above the rail line.
In Palo Alto, all options other than the berm remain. But the detailed analysis showed that the rail line could affect city life in various ways.
For example, building either an aerial viaduct or an open trench crossing the Menlo Park and Palo Alto border would adversely affect San Francisquito Creek (thus both options are no longer considered for that stretch).
Building an aerial viaduct between Embarcadero Road and Churchill Avenue would result in the loss of two traffic lanes on Alma Street. At the same time, traffic at Churchill could improve, since cars would no longer have to wait at the railroad tracks, the analysis states.
Some methods will be significantly costlier than others. Yet the Rail Authority did not eliminate any option solely on cost, according to the report. Rather, it is opting to design the whole San Jose to San Francisco corridor and then estimate the costs for each segment.
The Authority warned that the most costly of alternatives may not be feasible. If every segment of the line were to be built with the most expensive method, the cost for the whole route could be four to five times more expensive than what has been estimated.
"Such high cost alternatives would be impractical," the report states.
The alternatives will now be analyzed with greater scrutiny for their potential environmental impacts and engineering feasibility. That environmental impact study is expected to be completed by December 2010.
In addition to analyzing design options, the state agency also confirmed that it is still considering whether to build a mid-Peninsula station. If so, Palo Alto, Mountain View and Redwood City are all possibilities.
The Rail Authority held a board meeting in San Jose Thursday to review the analysis and receive public input.
Palo Alto City Councilman Larry Klein attended and warned that an elevated train track would be detrimental to Palo Alto.
"I'm here to speak first to the old aphorism from Tip O'Neill: All politics is local," he said.
"I think all transportation projects are also done to be local. By that I mean of course, this isn't a project that goes from Los Angeles to San Francisco. It also goes through many communities along the way.
"My message to you is — please engage us all in this process," he said.
"These are actual people, actual economies that will be affected by the routes that you choose as members of High-Speed Rail Authority.
"Let me close by invoking another aphorism: Do no harm."
The California High-Speed rail Authority Board voted 7-1 to accept the Alternatives Analysis Thursday, with Quentin Kopp dissenting and Vice Chair Tom Umberg absent. Kopp said that he wanted to see more discussion on options for the Transbay Terminal in San Francisco.