Just received verbal govt approval for The Boring Company to build an underground NY-Phil-Balt-DC Hyperloop. NY-DC in 29 mins. — Elon Musk (@elonmusk) July 20, 2017

The company is currently working on tunnels aimed at relieving congestion in LA. Musk tweeted that the New York-DC Hyperloop would be constructed in parallel (with city center to city center service, including up to a dozen entry/exit points per city), followed by a Los Angeles-San Francisco loop. He also envisions a Texas (Dallas-Houston-San Antonio-Austin) Hyperloop as a possibility. That's some pretty far-off planning.

For sure. First set of tunnels are to alleviate greater LA urban congestion. Will start NY-DC in parallel. Then prob LA-SF and a TX loop. — Elon Musk (@elonmusk) July 20, 2017

We're not sure who is going to work with Musk and The Boring Company on these projects (we've asked, but Musk hasn't responded). Chances are, though, that it will be Hyperloop One. The company recently completed a successful test of its mag-lev transport system, but even more importantly, it's staffed by former SpaceX workers and Musk is friends with its co-founder. We're skeptical that this project will ever happen, but you can't say that Musk doesn't have interesting ideas.