re: #76 Racer X

I like the idea of tunnels. Yes it is expensive but they last a long time. 10 Billion people is an awful lot of mouths to feed.

It may work in the distant future but as an investment that would mean a multi-billion dollar project that would be unproven to sustain itself in the free-market. I see it as first having to prove itself with elevated track with some tunneling since that can’t be avoided. Once it proves competitive then they can consider other options. First you build an airline, then you build the fancy airport.