As obvious as this may seem, though, it still needs to be said out loud because most of the journalists covering Elon Musk either don't understand this or choose to ignore it.
From Wired
Six months after Musk went on a Twitter tirade about LA traffic in December 2016, he had created the Boring Company, and was digging a tunnel under the parking lot at SpaceX’s headquarters in Hawthorne, California. The internet payment maven-turned-carmaker-turned-space enthusiast-turned-infrastructure baron has promised to completely change the way humanity bores tunnels, pledging make boring as much as 15 times faster, and reduce its cost by a factor of ten.
Thus far, the Boring Company is leaning on two used tunnel boring machines, and has yet to unveil any novel tech. But Musk did recently show off a completed, 2-mile proof-of-concept tunnel in Hawthorne, which begins in the parking lot of SpaceX’s headquarters.
Though I suppose we can't say for certain, it certainly appears that the digging here was done in a completely standard way using conventional (and not even new) equipment. It is, therefore, not a "proof of concept" tunnel, but rather just a tunnel. It is not particularly wide or particularly long. It was not dug under notably difficult conditions. It is just a tunnel.
For those of you who follow the Hyperloop coverage, this is a familiar turn of events. Despite the "dawn of a new age" rhetoric of most of the reporters, all of the demonstrations to date have been entirely limited to mature, well-established technology. We already knew that maglev trains and linear induction motors worked because we've had them for years. There was nothing more groundbreaking in these displays than in your typical, second-place science fair exhibit.
Now on to the good stuff.