Why can't the railroads and transportation companies create a consortium to rebuild the national rail infrastructure that uses a cheap alternative to petroleum and so competes with the airline industry? Just imagine zipping across the country at 800 or more MPH and going to New York from Los Angeles in 5-6 hours, by train, perhaps in a private cabin. As the world runs out of cheap petroleum over the next 50 years, the only other alternative to flying is rail unless some scientists invent a "Star Trek" type of teleporter or George Jetson provides us with a practical flying car.

Well, if common sense would reign, the Northeastern cities would be connected with highspeed trains linked to the airports. I think that there actually are faster trains from Boston to Washington, but they are not connected to the airports and not that fast. If you look at Europe, the German ICE travels at 150 mph, the TGV up to the 200s, and the transrapid operating in China reaches the 300s (I don't think anyone is aiming at 800 mph, though). One could declog the Northeastern airports for longer flights and offer transportation options which are more convenient and friendly to the environment (not cheaper, though). But this idea would probably require a government sponsored effort which would be fighted by lobbyists.

airplanes go fast because they are up where the atmosphere is thin. On the ground, 800 mph would cause a lots of air resistance and friction. In Europe, trains are more prevalent, and of course, were attacked by terrorists in 2004.

Well, you can attack about anything, from planes to busses, the attacks on (by the way mainly local/commuter) trains in Europe do not suggest any weakness of railways to terror attacks, so this is not a valid argument when comparing train and air travel. If you want to advocate individual car travel where it will be rather hard to achieve mass casualties, go ahead ...

"If you want to advocate individual car travel where it will be rather hard to achieve mass casualties, go ahead ..."

And THAT is one of the many reasons why I love having a car. I have participated in public transportation, and dislike the experience, even without it being a terror target.

Operating a train at 800 MPH would generate a shock wave which would remove roofs, flatten crops, and burst eardrums for miles on each side of the track. An evacuated tunnel has been suggested as a possible solution for that problem, but I don't expect that to happen.

Larger, although much lower speed, trains might be considered. I believe they are now on the order of 10.5 feet wide. If that width were increased to about 15 feet (not an inconceivable size) then reasonably sized cars might be driven into transverse pigeon holes at any point along an appropriately configured station. Two decks could be accomodated with little increase in height. If a room (with bath) similar to a motel room adjoined each car slot, then a perfectly acceptable means of travel at reasonable speed, and in reasonable comfort, might be attained. An additional couple of feet on the width of the train might allow occupants to move from one location on the train to another, although I think that the inclusion of vended food and drink in each roomette would be more practical, although people would be restricted to their own space for the entire trip. One 24-hour period on-board might allow a trip halfway across the country E-W or all the way across N-S, in many cases. I think that crossing the Rockies, for instance, at that kind of speed might be difficult unless unreasonable energy waste or incredibly long tunnels were incorporated. However, I think this kind of travel is on the edge of reality now, and might become more competitive later with increasing energy costs and air route congestion.