But is transit success holding the prospect of cleaner air hostage? It doesn't have to, but diesel appears to remain the fuel of choice for the Transit Authority -- there are no plans to buy alternate fuel buses in the anticipated purchases. More people riding the buses and subways is "good news," said Rich Kassel of the Natural Resources Defense Council, "but the ridership increase shouldn't delay the clean bus program."

Big orders of new diesel buses fly in the face of the MTA's January 1997 commitment to convert three depots and purchase 500 compressed natural gas (CNG) buses by 2001. NYC Transit already has a CNG refueling station at its Gleason depot in Brooklyn, and has operated 34 buses in Brooklyn since November 1995.

Transit has not yet chosen a Bronx or Manhattan depot for CNG equipment, which it had promised to do by July. In addition, the recently released MTA 1998-2002 Strategic Business plan, a high profile document that sets the tone for the direction of the agency, is silent on the Bronx/Manhattan CNG program. Manhattan, which is soon to be even further out of compliance with stricter EPA pollution rules, needs to get overall emissions down sooner rather than later. But the MTA still plans to buy 593 new diesel buses -- 350 of which were approved by the MTA board in March without debate.

While the 500 buses could be seen as an opportunity to begin converting the fleet to CNG, "the MTA says it doesn't want to expand the program until they've tested more of the CNG buses," said Kassel. But he added that "buying 600 new diesel buses is a missed opportunity to give New Yorkers cleaner air."