Elon Musk has been talking about The Boring Company, his tunnel-digging endeavor, for months now. Today, he tweeted, “Just received verbal govt approval for The Boring Company to build an underground NY-Phil-Balt-DC Hyperloop. NY-DC in 29 mins.”

Ars has reached out to Musk directly and to The Boring Company’s media contact to get more details on the “verbal govt approval.”

Ars also contacted the US Department of Transportation, and a White House spokesperson noted, “We have had promising conversations to date, are committed to transformative infrastructure projects, and believe our greatest solutions have often come from the ingenuity and drive of the private sector.”

It’s worth noting that back in January, Musk signaled his willingness to work with President Donald Trump, who made $1 trillion in infrastructure spending through public-private sector partnerships a tenet of his campaign. Musk became a member of President Trump’s Strategic and Policy Forum, although the Tesla and SpaceX CEO quit his advisory position when Trump announced his intention to withdraw from the Paris Agreement.

Now, I realize we’re in an age when the tweets of billionaires should be taken with a grain of salt. At first, The Boring Company really did seem like a joke, stemming from nothing but Elon Musk’s tweet about how he was frustrated with Los Angeles traffic. At the time, he also tweeted, “I am actually going to do this.” So I called CalTrans (the California Department of Transportation), which manages the state highway system, to ask if any such construction was in the works near California freeways. The CalTrans representative was as confused as I was and said he’d look into it. An hour and a half later, he called me back and said he had no idea what Musk was talking about.

But just a month later, when I was in LA for a Hyperloop competition on the SpaceX campus, a large hole was clearly being dug in the employee parking lot. In his remarks that day, Musk confirmed the construction was to test out a tunnel-digging project.

Since then, Musk talked about his grand plans to Bloomberg, showing off a used tunneling machine that he was considering purchasing (Bloomberg hints that the second-hand machine may have cost around $1.5 million due to a glut of machines in the market). The machine Musk was looking at could get through 300 ft of clay in a week—Musk told to the magazine that he wanted to build a machine that could dig a mile in a week.

The CEO eventually bought a used machine that he named “Godot” and has posted several pictures of it in holes. But boring’s not a priority yet, apparently. In a recent shareholder meeting, Musk said he spends “maybe two percent of my time” on The Boring Company.

So while we have no evidence that a super-fast tunneling machine is as plausible as Musk says it is, and even less confidence that Musk’s “verbal govt approval” will translate into something real (especially over state lines, where building massive infrastructure projects is contentious and time consuming—just look at California’s bullet train), we at least have confidence that The Boring Company isn’t a joke.

For now, though, all we have are tweets. Musk wrote this morning that the system, as he sees it, would go “city center to city center in each case, with up to a dozen or more entry/exit elevators in each city.” He also tempered his earlier statement a bit, writing, “Still a lot of work needed to receive formal approval, but am optimistic that will occur rapidly.”

So what’s the point of his recent statement? Possibly to drum up investors for The Boring Company. A reporter from the BBC tweeted at Musk asking why he’d say anything right now unless he’s looking for support. “Support would be much appreciated!” Musk tweeted back. It’s a tactic we’ve seen before from Musk—offer a grand vision that people are excited to buy into, and they’ll buy into it. This happened most recently with the “solar roof” announcement just before Tesla investors were expected to vote on whether the company should buy SolarCity—a proposition that many investors were skeptical of. At the time, Musk invited investors and press to a party with demo solar roof tiles on homes, but the undertone was that without a deal to buy SolarCity, the solar roof would never happen. Investors approved the SolarCity purchase by 85 percent.

Ars reached out to various tunneling experts about the plausibility of Musk’s plans two months ago, and Tom Ireland, a tunnel expert from the engineering consulting firm Aurecon, said he's interested in Musk’s ideas but noted that the limiting factor would be cost. “Historically, there are three elements that make up the cost of tunnel boring: equipment, materials, and labor, each making up roughly a third of the cost,” Ireland wrote to Ars. “If we see significant enough advances in tunnel boring and new materials (perhaps at the heart of Musk’s invention), cost will likely decrease sharply and make Musk’s futuristic tunnel system more achievable.”

“[W]e live in a complex transport environment where multi-modal solutions must be on the table, and for some of the world’s largest cities, this solution could be an attractive option,” Ireland also noted.

Of course, to make Musk’s vision pan out according to his tweet, we’d also need to see a working Hyperloop, and that seems to be a distant goal given what engineering teams have shown off so far. Even the venture capital-funded Hyperloop One only just did a test run of a magnetically levitating sled at 70mph this spring, which is a very preliminary step toward making any super-fast train-like transportation happen.

Update: A Boring Company spokesperson e-mailed Ars with the following statement: "The Boring Company has had a number of promising conversations with local, state, and federal government officials. With a few exceptions, feedback has been very positive and we have received verbal support from key government decision-makers for tunneling plans, including a Hyperloop route from New York to Washington DC. We look forward to future conversations with the cities and states along this route and we expect to secure the formal approvals necessary to break ground later this year."

