Re:Growing Caltrain into an 8-Lane Freeway (2018)
by marcinzm on Sunday January 06, 2019 @11:41AM
(#18839106)
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).
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Re:Growing Caltrain into an 8-Lane Freeway (2018)
by jacques_chester on Sunday January 06, 2019 @12:47PM
(#18839471)
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.
Re:Growing Caltrain into an 8-Lane Freeway (2018)
by marcinzm on Sunday January 06, 2019 @01:03PM
(#18839583)
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.
Re:Growing Caltrain into an 8-Lane Freeway (2018)
by bobthepanda on Sunday January 06, 2019 @01:37PM
(#18839764)
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.