When compared to single occupancy vehicles, public transportation produces 95% less carbon dioxide, 92% fewer volatile organic compounds, 45% less carbon dioxide, and 48% less nitrogen oxide.
Air Pollution Reduction Regardless of the type of fuel that a public transportation vehicle uses, riding the bus or taking a train helps to reduce air pollution.  For every person who leaves their car at home and decides to take a bus or a train, the amount of harmful pollutants entering the air decreases.  When compared to single occupancy vehicles, public transportation produces 95% less carbon dioxide, 92% fewer volatile organic compounds, 45% less carbon dioxide, and 48% less nitrogen oxide.  When these pollutants enter our atmosphere they contribute to global warming, smog, acid deposition, and health problems.