Not sure how this helps Tesla... I'm afraid this will reinforce the Wall Street belief that EM is taking on too many ventures of which Wall Street isn't going to value. If anything of this nature is announced the SP will take a hit. We'll probably get couple of FUD on this already... EM bored of money burning Tesla so now working on digging tunnels.
I really love EM's passion to solve humanitarian problems but this seems to be a project for the government... hmmm maybe being on Trumps advisory team he can have some influence here.
Maybe being on the advisory team got him thinking more about infrastructure and civil construction. Especially how it is a key plank in Trump's administration to help rebuild infrastructure and increase jobs.
While I don't disagree that the FUD-sters are typing up their new titles on this one, it would be a truly clueless one to not see the interesting "coincidence" of his Tunneling tweet and his recent meeting with Trump.
Heck, if the government wants to build the infrastructure, it's going to have to hire people/companies to do it.