

Intercity buses are one of the greenest ways to travel.
Sustainable transportation geeks give trains lots of love, but tend to overlook buses. That's a mistake: buses are surprisingly green. This report, for example, finds that buses are pretty much the most fuel efficient way to travel between cities -- better, on average, than rail, cars, or airplanes.
Of course, you can't just trust one report -- especially one that was funded by the American Bus Association. But plenty of other people have found the exact same thing. Our research on greenhouse gas emissions per mile of travel found that inter-city buses have the lowest climate impact of any form of travel. Rhe authors of the Consumer's Guide to Effective Environmental Choices -- which is a bit out of date now, but still excellent -- found the same thing. So did the Environmental Defense Fund. I could go on; but the bottom line is that people who care about sustainable transportation find that intercity buses are a pretty good deal for the climate.
There are two key reasons why intercity buses are so fuel efficient. First, the average intercity bus in the US carries about 21 passengers at a time (calculated form tables 1-32 and 1-37 of the Bureau of Transportation Statistics National Transportation Statistics report.) Second, they get about 7.3 miles per gallon (calculated from table VM-1 of the Federal Highway Administration's Highway Statistics Series.) Put those two numbers together, and you find that a bus gets about 155 passenger-miles per gallon of fuel. Not bad -- that's nearly as good as a Prius carrying a driver and three passengers!
So it's probably a good thing that the intercity bus industry was reporting a record increase in travel in 2008. And if higher ridership meant more passengers per vehicle, then buses probably got even more fuel efficient than the numbers I ran would suggest.
Obviously, bus travel isn't for everyone. But I've found that the service between Seattle and Vancouver is about as fast, and at least as reliable, as the train. All of which suggests that buses deserve far more attention than we give them.
This piece originally appeared in Sightline Institutes blog, The Daily Score.
Photo credit: flickr/G. McFly, Creative Commons License.
What about when you factor in the per mile, per year petroleum costs of maintaining the roadway versus the railway? No matter how efficient cars, busses and trucks may be on their own, when you factor in the petroleum content of the asphalt, the petroleum needed to get all of the asphalt, etc, there and all of the petroleum used to run the various machines to build and maintain the roadway, then there is no contest.
So, I agree that we need to think out of the box, and keep our eyes open to things that don't instantly seem so green, but we also have to take into account all that is needed for various solutions, none of them are closed systems unto themselves.
I have ridden the inter city buses on the north east corridor (NY/Boston and NY/DC) many times and find them to be reliable, fast and cheap, if a little more cramped.
I have read and heard (from people like Amory Lovins) that a tremendous amount of energy for any vehicle is expended pushing air out of the way. I think about inter-city buses with their flat fronts that are probably 14 ft high and 10ft wide and i can't imagine a less aerodynamic design, not to mention the open wheel wells and the flat back.
Are there any efforts underway to improve the aerodynamics and thus fuel efficiency of these inter city buses?
Apparently we must account for the highway construction, but can ignore the energy cost of rail construction and maintenance? Using this logic, air travel looks much better than both as it clearly requires the least amount of infrastructure per passenger-mile.
In the end for both bus and rail, the infrastructure they use are (1) built usually for other purposes anyway and (2) the actual construction energy consumed will pale in comparison to vehicle energy consumed in the life of the infrastucture. And using each's own reports, Greyhound is 3 times, 3 times more efficient than Amtrak. Even using the most creative math, you aren't going to make that difference up based on construction.
