Comment by phlakaton

Reports I read on this a month or more ago suggested that yes, part of his goal is to improve the speed/cost of building tunnels, so that it's feasible to go build a whole bunch of them quickly.

(That being said, building a bunch of tunnels in the bosom of San Andreas strikes me as hubris... But having lived in LA and its traffic for many years, I'm willing to be convinced. :-) )