Buses and Trains

How do buses and trains produce pollution?
BUSES
Like cars and trucks, most buses burn diesel, a hydrocarbon-based fuel. When vehicles burn fossil fuels, the combustion process also produces nitrogen oxides, particulate matter, carbon monoxide, and other pollutants.

TRAINS
Many trains use coal as fuel. Burning coal produces a lot of particulate matter (soot), sulfur dioxide, and other pollutants. However, a lot of trains also run on electricity, a much cleaner technology.

Buses use lot of gas and create a lot of pollution, especially when they sit idling at bus stops, BUT the 40 or more people on the bus aren't driving 40 cars - and there would be a lot more pollution coming from those cars than from the bus. The major air quality problems from bus emissions are in Southeast Asia, where there are many more buses than in the U.S., and where many buses still use leaded fuel. Trains are similar to buses in that they carry a lot of passengers so the overall pollution is less than if each passenger drove to the destination.

Are there laws regulating this pollution?
City and/or state governments in the U.S., not federal governmental agencies, implement most laws governing bus emissions. School bus fleets, because of the exposure to children, get most of the attention nationally. Trains operating in federal non-attainment areas for Criteria Pollutants could be subject to Clean Air Act regulations, but trains, like buses, are generally more of a solution than a problem.

How could they be made to produce less pollution?
BUSES
Buses in many areas are also now running on alternative fuels like ethanol and fuel cells, which makes them an even cleaner transportation choice. Some cities are also trying out electric buses.

TRAINS
Many cities have constructed electric trains, which are super clean.