I got some clarification on what happens now with BART to Warm Springs, assuming Measure B fails. As long as the Valley Transportation Authority Board approves going ahead with some version of the BART extension in Santa Clara County at its meeting in January, as expected, the Warm Springs extension can continue on schedule with bids going out in February.
About $300 million of the money for the Warm Springs extension is contingent on the VTA having a committed funding plan to build BART to Santa Clara County. Measure B would have provided funds to operate the future service, but the VTA apparently still has funds from a previous tax measure to build and operate a shorter route that might not make it all the way through San Jose.
The VTA President and San Jose mayor have said publicly that the county should go ahead with the Santa Clara extension, even if the money won’t be there to bring BART all the way into the heart of San Jose.