to save on fuel cost but spend a lot of money running pumps to keep a tube near vacuum ? these people are insane... just like building a tunnel to drive a car back and forth and pretend like its some new innovation, if only they knew of trains and trains that move underground in tunnels.
Commercial jet aircraft fly at 30,000 feet ~4psi to save on fuel which also translates to higher speeds, which was the joke. Hyperloop was supposed to be lower at ~0.1 psi mostly to allow for higher speeds.
As to the effort to maintain a low vacuum, that has relatively minimal associated energy costs assuming the track is reasonably air tight.
do you know how hard it is so keep vacuum? let alone massive tubes ? imagine just the temperature differences on day to night cycle and the overall length
just look at the energy cost and how much a pump can do in a reasonable time period vs the volume of a large distance tube.
