I'm honestly not properly educated to answer that. My responsibly on the team has been controls & networking. I don't think the tube necessarily has to be perfe

I'm honestly not properly educated to answer that. My responsibly on the team has been controls & networking. I don't think the tube necessarily has to be perfectly straight as the pod could bank on the turns like a racecar or roller coaster. I think the tube itself could be made reasonably cheaply compared to the CA high speed rail system. We transfer oil in huge pipelines with high pressure differences so I think it should be pretty feasible to keep it properly sealed. I'm more worried about the cost of the safety mechanisms and them being able to secure the land rights. Elon mentioned at design weekend that initial versions could even use wheels if they aren't going over ~250MPH.