Yeah - the elevation of the rails wouldn't have to be all that high, and would be mostly done over land that's easy to get to support such structures.
The thing is, this may be expensive, but it seems to me it is the most likely doable system of anything out there being proposed right now. Trucks and cars are both in extremely serious trouble from several attackers - the biggest two being the oil situation with unsustainable high prices (or prices so high that prosperity is unsustainable) and the environmental bunch (again) claiming the earth will burn to a cinder if temperatures rise to the same level as they have been in the past.
Use of electricity to move people and cargo at high speed over land solves a whale of a lot of problems if it can be made to work. Using nuclear generated power, it would be both an oil and a global warming answer for the transportation sector. Then we can look at the other problems.
Traffic accidents are a huge problem that costs thousands of lives a year. This could be reduced significantly if people, whose mistakes cause most of the accidents, were taken out of the control loop.
And, while other solutions such as hydrogen and hybrid drives help, they rely on the public buying them. Replacement of the oil-hungry private vehicles relies on people buying new technology cars, which would take many years for all the old technology to be taken off the road. A rail system, OTOH, would move vehicles that never even heard of a catalytic converter with zero pollution - even a model T - buttuming a clean power source like nuclear or wind or solar or geo-thermal or future power sources like nuclear fusion are used.
Then there's the economic aid of being able to move things, cargo and people, around at high speed automatically, with no human intervention. 150 mph land travel that doesn't move on a schedule can compete with 500 mph air travel that has to wait for an airplane to leave on schedule. Live in Indianapolis and want to go skiing in Colorado every weekend? Drive to the rail station after work Friday night, drive your car onto the railcar, dial in "Vail, CO", and in less than 7 hours you arrive at your destination, in time to see Jay Leno on the tube and get up the next day and ski. And, you're not going to get in an auto accident or get chased by the cops for speeding.
As for expense, the interstate highway system was built, and would look to be prohibitively expensive. But it wasn't. The elevation of rails might only be necessary in very densely trafficed areas, like near cities, otherwise allowing the rails to be laid directly on the surface, reducing costs.
Dave Head
