Clean diesel produces fewer hydrocarbons and carbon monoxide as well. Both are greenhouse gases. Each of the transit agencies had to consider the added expense if they chose natural gas. But for many agencies, it was the increased yearly operating costs and service concerns that fueled the final vote for clean diesel, according to Diesel Technology Forum spokesperson Pam Jones who testified at hearings of the seven major Northern California transit districts. Paradoxically, the higher CNG price tag could result dirtier air because fewer dollars would be available to retire old, dirty buses.
Fewer buses mean more people in cars.
At San Francisco Muni, which already meets 2007 state clean air standards because 40 percent of its buses are electric and produce no emissions, General Manager Michael Burns pointed out the dilemma. For Muni, that means the continued use of electric trolleys and diesel buses fueled with low-sulfur fuel and equipped with improved emissions controls. Last summer, the District mandated all public transit fleets with its jurisdiction to purchase alternate fuel buses despite evidence that clean diesel could been the same state standards and do it faster and cheaper. The diesel buses can run at 60 miles per hour, he added. In the Sacramento Valley, 40-bus Yolo County Transportation District has chosen to continue to build its CNG fleet.