Not so friendly reminder that musk specifically came up with, and pushed, for hyperloop knowing that it would never be made, as an effort to stop the development of highspeed rail in America and shift all political discussions of it because "something better is around the corner":
As I’ve written in my book, Musk admitted to his biographer Ashlee Vance that Hyperloop was all about trying to get legislators to cancel plans for high-speed rail in California—even though he had no plans to build it. Several years ago, Musk said that public transit was “a pain in the ass” where you were surrounded by strangers, including possible serial killers, to justify his opposition.
Also: 2024 update, the total length of China's high-speed rail tracks has now reached well over 45,000 km, or 28,000 miles, by the end of 2023.
They are additionally five years ahead of schedule and expect to double the total number within ten years. And, before someone inevitably complains about "how expensive it is", they are turning over a net-profit of over $600M USD a year.
The Big Dig didn't cost that much in the end ... about 1/4 of what Musk paid for Twitter. If a billionaire could throw money away on a vanity social media project, than the government could spend a quarter of that on critical infrastructure.
The biggest cost of the big dig was the opportunity cost. The state let the mbta (the metro and commuter rail) fall into a state of comical disrepair. Trains aren't supposed to catch fire or derail as often as the T does