Last week, Pennsylvania Gov. Ed Rendell said, "Let’s end air travel of less than 500 miles."
This isn't the first time we've heard this. It is one of those ideas that sounds nice but unravels once you start looking into the details.
High-speed train proponents in California, the Obama administration, and others have talked blissfully about the time savings that could be provided by taking a high-speed train from city center to city center. That may well be where many people want to go in the Northeast Corridor, but in the South and West, people mostly want to go from suburb to suburb, so the door-to-door trip time is likely to be the same or greater than for taking such trips by plane.
More important, the aviation and highway systems pay for themselves—the user taxes and fees people pay cover the capital and operating costs of airports, air traffic control, and inter-city highways. By contrast, a national system of high-speed rail for trips up to 500 miles would take something like $500 billion of taxpayers’ money. And after that massive subsidy, maybe the operating costs would be recovered from passenger fares (though even that is doubtful, based on overseas experience). Reason's analysis of the California high-speed rail proposal found "the San Francisco-Los Angeles line alone by 2030 would suffer annual financial losses of up to $4.17 billion."
As for carbon footprints, by the time (say 30 years from now) that such a high-speed rail network could be completed and in operation, both cars and planes will be dramatically less carbon-intensive, while trains (as long-lived investments) will likely have the same carbon footprint as they have today. So the next greenhouse gas reductions from the rail network would be very modest—and achieved at a massive cost per ton of CO2 reduced.