On these pages and elsewhere, I sometime see posts which claim that all our energy security, CO2, and other environmental ills will be magically cured if only we would make the effort to deploy some innovative technology, which for the transportation sector is commonly presented in terms of expanding the rail network at the expense of flying. In fact, the Transportation Energy Data Book seems to support this, as summarized by the National Association of Railroad Passengers :
in 2005, domestic airlines on average consumed 20.5% more energy per passenger-mile than Amtrak, while cars consumed 27.2% more than Amtrak. Looked at the other way round, Amtrak consumes 17.0% and 21.4% less energy per passenger-mile than airlines and cars, respectively. [One passenger-mile is one passenger traveling one mile.]
Unfortunately, figuring out what's best for you is more complicated, and, even worse, rational policy alternatives are bitter political medicine, as I'll explain below the fold.
The superior performance of rail is based on a per passenger mile basis:
Those percentages are derived from these Oak Ridge figures (British Thermal Units or BTUs per passenger-mile, 2005 data), organized here most to least efficient:
Amtrak: 2,709
Commuter rail: 2,743
Rail transit: 2,784
Certificated air carriers: 3,264 (excludes international services)
Cars: 3,445
-from NARP press release
So I attempted to calculate the footprint of a recent vacation trip I took to Yellowstone National Park. I traveled from Baltimore, Maryland by rail; the alternative would have been to fly to Bozeman, MT via Minneapolis. The nearest railhead is Havre, MT, which rquires a 300 mile drive to Bozeman, where I picked up by roomate at the airport and drove into the park. No need to bore you with bottom line CO2 or energy consumption numbers, as those are given on a per passenger-mile basis, thus the miles traveled are directly proportional.
First, the rail trip required 600 additional auto miles not needed for the trip by air. But also, the round-trip air maileage from BWI to Bozeman via MSP was about 3600, whereas the round trip rail mileage from the BWI Amtrak Station to Havre was about 4200. After all planes can travel "as the crow flies," ground transportation has curves and twists to overcome the topography.
OK, one might say that a trip to a part of the country with lousy train service isn't a fair comparison, and, indeed, one day, I hope that Amtrak revives the North Coast Limited that used to stop in Bozeman and would eliminate both the extra miles the current train runs to Northern Montana, and the 600 mile auto trip. But here are some other city pairs:
BWI -- Chicago: Rail: 800 miles, Air, 600 miles (rail has 30% more miles)
Washington -Boston: Rail: 450 miles, air: 398 miles (rail has 13% more miles)
Washington-Pittsburgh: Rail 283 miles; air 205 miles (rail has 38% more miles)
Air miles from:
http://www.webflyer.com/...
Rail miles from Amtrak timetables
I myself was surprised that the rail advantage in per passenger mile fuel consumption was small enough that it's mostly offset by the decreased mileage required by air travel.
There are further complications, of course. Rail has advantages in that it's terminals can be fit directly into a pedestrian/transit friendly environment. Also, the source data suggest that the rail performance is based on very low load factors (perhaps less than 20 people, whereas airline load factors are on the order of 75% of planes with capacities of 100+. Changes in rail operations that reduce the transport of deadhead (empty) cars and switcher engine operation could go a long way to improving rail performance on fuel economy.
But these numbers suggest that getting serious about reducing fuel use and CO2 emissions is really about reducing total miles traveled. In the the words of James Howard Kunstler, "The future will be about staying where you are, not traveling places." At least not traveling as much as Americans are used to. And I'd be very surprised to see any American politician of either party gain any success telling people that. For a red-blooded American, that's bitter medicine to swallow. For a red-blooded American politician, it may well be poison. Actually, I'm very pessimistic that the public will understand this until its too late and our economy collapses. And then we'll all be stranded.