NEW YORK — This year, the surging current of the East River will help provide power to a nearby subway station. The lights that lace the ornate interior of Manhattan's Grand Central Station have largely been replaced by bulbs that burn brightly but save energy. There are plans to make the rooftop of a Queens bus depot bloom like a garden.

"Carbon footprint" has become part of the national lexicon, and mass transit systems throughout the country are taking steps to ease their impact on the environment even as they strive to provide more service to a growing number of riders.


New York's Metropolitan Transportation Authority, the nation's largest public transit agency, is undertaking what some experts call the most comprehensive effort, but examples abound of bus and commuter rail systems trying to preserve the environment.

"The transit industry is no different from the rest of the country," says William Millar, president of the American Public Transportation Association, which lobbies to improve public transit. "We're all looking for ways we can do a better job … but at the same time put out less pollution and fewer carbon emissions."

According to the APTA, members of households closest to public transportation drive an average 4,400 fewer miles a year than those who aren't near bus or rail lines. That reduces the nation's carbon emissions by 37 million metric tons a year, equal to the electric power used by 4.9 million households.