Hypothetically, the vacuum tube gives you energy efficiency. Drag power is proportional to the cube of velocity, so drag energy losses over a fixed distance ar

Hypothetically, the vacuum tube gives you energy efficiency. Drag power is proportional to the cube of velocity, so drag energy losses over a fixed distance are proportional to the square. In an ideal world you're paying a fixed cost per unit time to pump the tube down then you shove as much stuff as you can through it at transsonic speed, catch it all with regenerative brakes at the other end, and pay an energy per kg payload cost lower than electric road vehicles. Of course in practice that fixed cost may turn out astronomically high, but that's the idea.