Is A Prius Greener Than Light Rail?

"Light rail in practice uses about as much energy to move a passenger a mile as does your average car, reports transit expert Randal O'Toole of the Cato Institute, the libertarian think tank. When it comes to carbon dioxide per passenger mile, light rail beats the average car only in some cities -- mainly where electricity doesn't come from coal or oil. Nearly everywhere, you put out less carbon by driving a Prius than by taking the train.

This isn't what most people expect. Still, O'Toole, a longtime critic of light rail, confined himself to data from federal transit and energy agencies. When I checked with head researcher Steven Polzin at the transit-friendly National Center for Transit Research, he said the numbers were good and the conclusion true. Most people assume rail is far more efficient, "but the empirical data isn't very compelling," he said."

"If you fill the trains, per-passenger energy use is lower, but, says Polzin, the average load per railcar has fallen in the long run as rail expands to more marginal markets. The share of commuters taking public transportation has fallen in 20 of 25 cities since the installation of light rail or, for older systems, since 1970, say federal figures. Most of those lured by trains came off buses, not out of cars.

The upshot, says O'Toole, is that while light rail puts out about 0.36 pounds of carbon dioxide per passenger mile - and more than a pound a mile in Baltimore, Pittsburgh or Cleveland - a hybrid Prius puts out 0.26."

"Minneapolis actually did lower carbon emissions with its light rail line, saving 16 million pounds of carbon dioxide when passengers switched from buses. It's also saving millions more by replacing old buses with hybrid-electrics. But while light rail cut carbon at a cost of $2.20 a pound, says O'Toole, buses did it for 60 cents."