How Public Transit Helps Reduce Air Pollution:
Public transit moves people efficiently while producing significantly less air pollution to move one passenger one mile -- compared to moving a person one mile in a single-occupant auto.
Buses emit only 20% as much carbon monoxide per passenger mile as a single-occupant auto.
Buses emit only 10% as many hydrocarbons per passenger mile as a single-occupant auto (hydrocarbons are VOCs – an ozone precursor).
Buses emit only 75% as many nitrogen oxides (another ozone precursor) per passenger mile as a single-occupant auto.
Trains emit only 25% as many nitrogen oxides per passenger mile as a single-occupant auto, and nearly 100% less hydrocarbons and carbon monoxides.