The bond measure is only a first step in a massive undertaking, estimated by the rail authority to cost in excess of $40 billion. The state must attract matching federal funds, additional local funds and donations from the private sector before trains will be up and running.
Under the plan, high-speed trains would connect to Gilroy from the Central Valley, and shoot up the Caltrain corridor to San Francisco, and then back.
If the project is built, it would require grade separations — separating the Caltrain tracks from the roadway at key intersections — and years of construction and traffic impacts as additional tracks are added for the faster trains.
The California High-Speed Rail Authority Board chose the route at its Dec. 19 meeting in Sacramento. No vote was taken, but there was no objection to the choice of Pacheco Pass as the preferred route, said Dan Leavitt, high-speed rail authority deputy director.
Politicians and environmental groups point to high-speed rail as a big step toward cutting greenhouse gas emissions. They see high-speed trains as an environmentally friendly alternative to congested freeways and air travel, and vital to accommodating the state's growing population.
The trains would whisk passengers from San Francisco to Los Angeles in about two-and-a-half hours. As proposed, the high-speed rail network would eventually stretch from San Diego to Sacramento.
But the fate of the project still depends on a $10 billion bond measure slated for the November ballot.
In the past, bond measures for high-speed rail were pulled from the ballot by the state Legislature and Gov. Arnold Schwarzenegger due to the staggering costs. The same thing could happen this time around.
If the bond measure stays on the ballot and passes, and other funds are found, Mr. Leavitt said, the connection from Los Angeles to San Francisco would be the first segment built.
High-speed trains could stop in Palo Alto or Redwood City, although those details are still uncertain, Mr. Leavitt said.
Menlo Park Mayor Andy Cohen, who lives near the Caltrain tracks, is less than thrilled with the idea of high-speed trains zooming through town.
"It's an ill-advised extravagance," Mayor Cohen said, echoing critics of the project who say costs will skyrocket far above the projected $40 billion price tag, and construction noise and traffic impacts will seriously affect nearby homes and businesses.
"It's not going to help people get around town, or even the Peninsula," he said. "It's some grandiose scheme to connect Los Angeles to San Francisco, and there is zero benefit to Menlo Park."
But high-speed rail supporters such as Jim Bigelow, chair of the Menlo Park Chamber of Commerce Transportation Committee, say high-speed rail is about thinking regionally, not locally.
"High-speed rail is an alternative that's quiet and comfortable," Mr. Bigelow said. "You have to be a little bit of a visionary, and think about how [high-speed rail] can ease the demands on the state's transportation system."
Atherton Mayor Jim Janz said the town has stated a preference for the alternative that would traverse the Altamont Pass. "We're not eager to see high-speed rail coming through town," he said.
But even if the system is built on the Pacheco Pass route, the train could still be directed along an alternative route through the Peninsula, such as one parallel to Interstate 280, he said.
If the route along the Caltrain right of way is ultimately used, he said, the town is likely to advocate that the tracks be run through a trench or tunnel.