Elon Musk actually built that tunnel under L.A.—but it’s probably not what you were expecting

“Eccentric billionaire invites citizens to opening of new underground tunnel” is the sort of headline that seems like it should only exist in comic books. But there we were last night, watching as Elon Musk unveiled a 1.14-mile-long tunnel underneath Hawthorne, near the SpaceX headquarters. We should clarify that by “there we were” we mean we were curiously tuned into a livestream of the invite-only unveiling (Musk must’ve dropped our invite somewhere in the tunnel).

Two years ago almost to the day, the Tesla and SpaceX founder tweeted about how much L.A. traffic was driving him nuts and mused about digging a tunnel underneath the city. That tweet birthed the Boring Company and, by a few months later, a grand vision of high-speed skates throttling cars through dense networks of tunnels at up to 124mph.

Fast forward to Tuesday night, when Musk emerged from the test tunnel after a 40 to 50mph drive in a Tesla Model X outfitted with roller-coaster-like retractable wheels.

For starters, the tunnel appears much narrower than we ever expected, its claustrophobic contour barely wider than a car (we sure wouldn’t want to try evacuating one by foot). Then there’s the skate, or rather the lack of it. Here’s the tunnel system’s initial rendering, for reference.

In its place are retractable side-facing wheels that Musk says could be outfitted on any autonomous electric vehicle.

By all accounts of people there who went for a spin, the medium-speed ride was pretty bumpy (“It’s going to be a slightly bumpy ride, it’s a little rough around the edges,” remarked Musk.) He still insists that the system is designed to reach speeds of 150mph, but currently even 110mph is “a little scary now.”

For Musk, the Boring Company venture seems all about the noble goal of increasing the speed and lowering the cost of tunneling. “We need to be able to build tunnels way faster and for a hell of a lot less money,” he says. About 15% of the cost is tied to trucking dirt out, but Musk plans on recouping that by turning all of that dirt into bricks and selling them at $.10 each. He estimates the cost of the roughly mile-long test tunnel at about $10 million; by comparison, Metro’s Purple Line subway extension is totaling over $700 million per mile.

But a Metro train can carry dozens of passengers—who don’t need to own or hail an autonomous electric vehicle—at a time. Musk’s single-lane tunnels, by comparison, can accommodate a car’s worth of people. Theoretically, one car per second could pass through the tunnel, roughly double the efficiency of a normal freeway. So Musk’s solution? More tunnels, layers upon layers of them, three of four deep, forming a 3-D tangle of tunnels underneath Los Angeles accessible via prefab car elevators.

There’s a lot that stands in the way of Musk’s tunnels: property rights, environmental laws and community pushback, which has already forced the Boring Company to pivot away from plans for a tunnel underneath Sepulveda Boulevard and toward one to Dodger Stadium. Then there’s the matter of whether or not these would actually do anything to ease traffic, or if they’d just create a different type of gridlock. “I’ve lived in L.A. for 16 years,” says Musk, “and traffic has gone from the seventh level of hell to the eighth level of hell.” We’re not quite sure yet at what level a narrow car tunnel will reside.