There seems to be no active faults crossing Caltrain Tracks between SF and SJ.

http://quake.usgs.gov/info/faultmaps/122-38.html

FYI, there are 12 tunnels crossing active faults in Shinkansen (it could be more if there are undiscovered faults). However, none of the active faults that Shinkansen tunnel is crossing have drift rates comparable to San Andreas (source-wikipedia).

I'd be very surprised if it wasn't. I'm not saying tunnel or nothing – I don't live on the Peninsula now but I grew up there so I'm quite familiar with it and I don't think that a well-designed elevated line is quite the visual disaster that it's opponents claim. However, I do think that a tunnel is the best solution if it's designed right and if a funding solution can be found that's workable for all parties, so I'm glad CHSRA is considering it and I'm curious to see what they come up with.

What I find silly is the implication from some commenters that Palo Alto, et. al., are somehow acting in bad faith by proposing a tunnel and not volunteering to pay for it. It's not like Berkeley decided to pay for their BART tunnel because they felt it was the Right Thing to Do; they only raised taxes for it after cost estimates were in place and it became clear that there would be no other funding available. It's only rational to expect the Peninsula cities to do the same.

"Surveying shows a drift at the rate of as much as 2 inches per year."

Which faultline crosses the Caltrain ROW and has that amount of movement? Not saying you're wrong, I'm curious though because I've never heard this. Not sure how you run a tunnel through a faultline – the Japanese seem to have it figured out though.

"Surveying shows a drift at the rate of as much as 2 inches per year."

Regarding earthquakes – we're talking tunnels here, not coal mines. A properly constructed tunnel can handle a huge earthquake – even one that would level many above-ground structures. Seismologists have said that the subway is pretty much the safest place to be in Los Angeles when the next Big One hits.

As far as access for other types of emergencies, we're not talking about alpine base tunnels here, it's possible to provide numerous access points.

It's true that some people just don't like going into tunnels – I know more than one Londoner who favors the bus instead of the tube for this reason – yet it can't be anywhere near the number of people who are terrified of flying, yet the airline industry has done ok over the years.

I think the reason costs haven't been a big part of these meetings is nobody knows what those costs are yet, since these tunnels haven't been designed yet. And no, back-of-the-envelope educated guesses by bloggers don't count. And if you don't even know the costs, arguing about who is going to pay for things is fairly silly.

thank you for clarifying who brought up the issue of the view. I couldn't recall when I was supposed to have made that comment.

Your point about safety is well taken. By definition, tunnels are enclosed, confined spaces with a limited number of emergency exits. Earthquakes, fires, medical and sabotage/terrorist scenarios all have to be considered, even if they are very unlikely. For example, electrical fires on trains are extremely rare, especially compared to to risks posed by flammable cargo on freight trains, accidents in road tunnels etc. But still, the risk is not zero, it has happened before.

Another safety factor that is often overlooked is that of drivers suffering "tunnel vision", and I'm not being metaphorical here. Zooming through very long tunnels at high speed can temporarily impair peripheral vision and affect depth perception. The driver cabs windows on Eurostar trains are narrower than those on on other HSR trains to minimize the risk. Candidate drivers are also screened to weed out those who are more susceptible to the condition. Fortunately, shorter tunnels don't seem to cause as many problems.

As for passenger enjoyment, spending some fraction of an HSR journey underground is par for the course. A number of rail lines in the Alps are almost entirely underground. The planned Chuo shinkansen line (maglev) will also run in tunnels for much of the route. Those suffering from cuniculuphobia – I think that's the word for "fear of tunnels" – may want to stick with driving and flying.

"Sounds" wrong, in that case. I've ridden both the Eurostar and the Shinkansen. It's you who is relying on youtube and superstition. I'll admit, I riding the train itself doesn't give a perfect idea of what external noise levels are like (though on the Shinkansen they pass trains through stations all day at near full speeds, so I got a decent taste of it. And it's not that bad. Especially not at 125 mph.

As required by court order. I don't think they could have rescinded the EIR without doing it by public meeting, as per the Brown Act. (I could be wrong, I'm only vaguely acquainted with the Act)