Seismic activity will be taken into consideration.
Land rights are part of proposed cost.
Estimates based on current costs ... and Elon said likely to find more efficiencies to make it cheaper ...
(S)he didn't say it was. (S)he said "near vacuum." And that comes straight from the hyperloop paper:
"Just as aircraft climb to high altitudes to travel through less dense air, Hyperloop encloses the capsules in a reduced pressure tube. The pressure of air in Hyperloop is about 1/6 the pressure of the atmosphere on Mars. This is an operating pressure of 100 Pascals, which reduces the drag force of the air by 1,000 times relative to sea level conditions and would be equivalent to flying above 150,000 feet altitude."
http://www.teslamotors.com/sites/default/files/blog_attachme...
Page 12: "The pressure of air in Hyperloop is about 1/6 the pressure of the atmosphere on Mars."
Sounds like a near vacuum to me.