Just read up on hyperloop. So basically it is a maglev train-like carriage (for passengers or freight) that gets rid of air friction by riding in a vacuum tube. That latest test was in a 500m-long vacuum tube.
Vacuum equivalent to a height of 200,000 feet above ground. That is 60km. For comparison: Jet aircrafts travel at altitudes of 10 to 15km, while the Kármán line, where space begins, is at 100 km.
The targeted speed of 700mph/h (it said in an article) is breathtaking (no pun). Biggest technical problem seems how to maintain vacuum in a tube not of a few hunfred metres but many kilometres in length.
There seem to be several companies working on that idea. For Elon, I guess, building it on earth is just a test, cos he seems to be thinking Mars again. :
Anyway, hyperloop is more of a train or public tranporation idea, while self-driving cars clearly address the idea (and illusion) of (emotional) freedom.
Vroum vroum!