[potatolicious]

BART is already built through the very same ground. MUNI already has multiple tunnels through the "mountains" in the middle of SF. BART even runs directly through artificial landfill without issue.

The seismic activity of California certainly exposes more challenges, but there's no good reason why underground transport is impossible in SF.

Bus Rapid Transit is a cheap way to look like you're doing something about transit in a growing city when in reality you're just kicking the problem down the line.

[sliverstorm]

BART isn't really "underground" though, right? I was pretty sure for 99% of its track it never goes deeper into the ground than an underpass.

[potatolicious]

Outside of SF yeah, a lot of BART is elevated or separated at-grade, but in the city proper it's definitely legitimately underground.

Which is the same as NYC - subways in the central bits, elevated/at-grade rail as you get further out and land less scarce.