LOS ANGELES (AP) — Elon Musk's already going high, and now he says he's going low.
In mid-December the billionaire tweeted "Traffic is driving me nuts" and "am going to build a tunnel boring machine and just start digging."
On Wednesday, the SpaceX and Tesla founder tweeted he plans to begin in a month or so at his Los Angeles-area rocket factory.
The statements have launched speculation about another fantastic transportation idea from Musk, who is known for advocating a "hyperloop" — a futuristic system of vacuum tubes with passenger-carrying capsules.
But Musk's cryptic tweets leave unclear what kind of tunnel he'll be digging.
One tweet said the starting point will be across from his desk at SpaceX in Hawthorne, California, but didn't say how big the tunnel will be or where it will lead to.