Every time Bay Area residents take a bus or a train to work instead of hopping in our cars for a traffic-congested commute, we make a dent in air pollution and help curb global warming. Motor vehicles are responsible for much of our air pollution and, along with other forms of transportation, produce about 57 percent of California's carbon dioxide -- the primary global-warming gas. The popularity of public transit is a good gauge of the Bay Area's progress in reducing health and environmental problems caused by dirty air. NRDC researchers found that between 1995 and 1999, the number of people using the Bay Area's eight major transit systems increased.

Findings
NRDC researchers examined ridership on the eight largest public transit systems in the San Francisco Bay Area, relying on data from the American Public Transit Authority. From 1995 to 1999 (the last year for which official data are available), travel on public transit grew, in some cases significantly. CalTrain ridership increased 56 percent while Valley Transit Authority patronage went up by 21 percent. The County Connection gained almost 21 percent. Ridership on both Golden Gate Transit and BART increased by almost 10 percent, although San Francisco Muni use was up a scant 0.3 percent. The only major transit service provider to lose ridership in this period was SamTrans, with a decrease of roughly 8 percent.