If we are talking of things that might not happen, won't it be much cheaper for BaRT and Caltrain to unify, providing seamless transfer between them, and increasing Caltrain frequency? This competition between Caltrain and Bart is doing more harm than good.

Caltrain and BART don't compete except for the Milbrae->SF segment. I don't think that the Caltrain ridership would be supportive of what would essentially be a BART takeover of the system, because Caltrain is so much more pleasant to ride. There are a lot of reasons for this -- different demographics of the areas served, commuter oriented schedule, and the different configuration of the trains themselves. One of the biggest though is the positioning and attitude of the employees towards troublemaking riders. If you're making a nuisance of yourself on Caltrain, the conductor will come through and throw you off the train. There is no conductor on BART, and the station attendants generally don't leave their booths. It's to the point where you can literally shoot heroin on a BART train and nothing will happen to you. Try that on Caltrain, and you will be thrown off and the police will be called. The net result is that on roughly the same segment, Milbrae->SF, if I can get a seat, I have no concerns pulling out my laptop on Caltrain. I wouldn't even consider this on BART, and I am even cautious pulling out my phone.

For a nice visual of the fiefdoms, check out the map here:

https://www.seamlessbayarea.org (From SPUR)

Don’t forget amtrak (it’s been running on the 880 corridor parallel to the new bart extension for decades), or ACE.

> It’d serve more people and would be more convenient than Caltrain's right-of-way.

Does it? They parallel each other with less than a mile between down most of the peninsula.

Bart lacks tracks for passing (though this could be added in new construction), and the Daly City route is a detour for most commuters looking to go to Downtown SF, so it's slower than most Caltrain trains.

Caltrain's also been able to handle capacity issues better because they buy off-the-shelf cars.

It seems more cost-effective to grade-separate and electrify Caltrain and run the extension to the Transbay Terminal. And fix the Transbay Terminal.

Does the soil support cut-and-cover? Most Bay Area homes I've seen don't have a basement, and I've always assumed that's for a reason.

I would think poor ground strength makes cut-and-cover even more attractive relative to the alternative (drilling). For tunnels drilled under streets, the street is supported by rock/soil. For cut-and-cover, the street is supported by concrete and steel.

Maybe you're thinking that it's just impossible to have shallow tunnels at all with the type of soil? I don't think that's how things work, but I'd love to hear from an expert.

Basements are expensive to build and the climate in northern california doesn't require you to build below the frost line like it does in the north. So nobody does.

Code doesn’t require it, and basements add building costs.

It's not just a bitter pill but a very expensive one. That's, what, 50 miles of tunnel at a cost of $300 to $800 million per mile (based on other US projects). That's $15 to $40 billion total which is a massive investment (BART's budget is only $700 million per year) and I somehow doubt even the high end captures the full cost (once NIMBY get's involved).

Cut & cover is not the same as tunnelling. The name says it all: you dig a deep trench (cut), build structures, then replace the road as the roof (cover).

It's typically cheaper and faster, as it requires very little in the way of special equipment or personnel. The downside is that it requires cutting up the road. The "bitter pill" here is the several years of traffic disruption that would be required.

Cheaper and faster does not mean it's cheap or fast. Traffic needs rerouting, existing underground infrastructure (water, power, etc.) needs to be handled, stations need to be built, ventilation needs to be built, etc.

The BART Berryessa Extension was above ground (even cheaper) and still cost $230 million per mile. So, yeah, I doubt cut and cover would be anywhere close to cheap.

Those are factors of all underground construction. Some of those are even factors of elevated or ground level construction, since utilities are rarely placed with foresight for things like tunnels, and you’re probably impacting road drainage and need to reconstruct wall to wall.

Cut and cover actually doesn’t really use ventilation; with enough openings to the sidewalk, trains will create a natural piston effect cycling air in and out of tunnels. That’s how the NYC subway operates.

>Those are factors of all underground construction.

Yes, my point exactly. Underground construction is not cheap.

More cars? Trying to figure out how to get more cars on the road?

That’s been the plan since the 1970’s.

Maybe they should have built the high-speed rail like they wanted at that time. It becomes more difficult and expensive as the decades progress.

No, they're saying Caltrain would contribute the same as 8 lanes worth of freeway commuter volume. But I think BaRT would be a better solution than Caltrain, if they put BaRT down the El Camino as it would serve a higher pop and would be closer to pop centers.

I responded to cut-and-cover comment. He wants to bury the train and build a road over it?

I understood the article.

El Camino is an existing road. OP is suggesting adding a BART tunnel beneath it to extend BART service from Millbrae through Silicon Valley.