Are buses the greenest form of transit?

By Roddy Scheer
Bus travel is an environmentally friendly way to travel.
Bus travel is an environmentally friendly way to travel.
Dear EarthTalk: I always assumed the train was the greenest form of mass transit, but a friend told me I would be better off taking the bus. Could this be true? 

-- Jane McNeil, New York, New York
     Most of us assume that train travel -- for getting around town, commuting to work or going for long hauls -- is the most eco-friendly mass transit mode. Indeed, trains seem greener, with some relying exclusively on electricity while others utilize a single diesel-powered locomotive to pull dozens of passenger cars.
     But while trains are no slouch when it comes to fuel efficiency, buses may be better -- even though they spew diesel exhaust and get only about 6 mpg. 
    “The reason ... is that they are usually full of people, giving [buses] the highest miles per gallon per passenger, at 208,” reports CNN’s Steve Hargreaves, based on his research digging into Energy Department data. He adds that trains are the next best choice for the eco-conscious traveler, whether commuting or doing a longer haul. “A city train (think subway or light rail) gets 52 mpg per passenger (or the equivalent, if it’s electric), while a commuter train -- usually used to connect the suburbs to a city -- gets about 44 mpg per passenger.”
     A landmark 2013 study in Environmental Science and Technology by researchers at the International Institute for Applied Systems Analysis and the Center for International Climate and Environmental Research backs up these findings. The researchers found that bus travel noses out rail travel in fuel efficiency and carbon impact on typical business or holiday trips ranging from 500 to 1,000 kilometers (300-600 miles), generating only about 20 percent of the per passenger emissions as driving alone in a typical gas-powered car.
    “Motor coaches leave carbon in the dust,” reports the nonprofit Union of Concerned Scientists, adding that a couple can cut their travel carbon emissions in half by boarding a motor coach instead of taking their Prius. “And if they take the motor coach rather than flying, they will cut their emissions by 55 to 75 percent, depending on the distance they travel.” Given that many bus companies have ditched their old buses in favor or new models replete with not only more efficient engines but also reclining seats, onboard entertainment and Wi-Fi, the bus could become your new favorite way to travel.
    Though buses are the current green leader, trains are catching up fast. All of Amtrak’s trains in its busiest Northeast Corridor now eschew the old diesel generators that used to power their locomotives and run instead on an increasingly renewable supply of electricity. A $10 billion investment in high-speed rail by the Obama administration means trains are getting more efficient across the country as well.
    As a candidate, President Donald Trump promised he would pour hundreds of millions of dollars into further boosting high-speed rail infrastructure, but his 2018 budget does more to decimate Obama’s progress on the issue than augment it. Whether he will follow through with a plan to bolster U.S. rail travel remains to be seen. In the meantime, while trains remain a viable green choice, choosing Greyhound over Amtrak might be the better option.


     Union of Concerned Scientists


     International Institute for Applied Systems Analysis

     Center for International Climate and Environmental Research



     Getting riders from bus to doorstep

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