Transportation also leads to noise pollution, water pollution, and affects ecosystems through multiple direct and indirect interactions. With the continuous growth in transportation, increasingly shifting to high-speed transportation modes, these externalities are expected to grow.
Public transportation gets people where they're going while emitting far fewer climate-warming greenhouse gases than private cars. The reason is simple efficiency: while cars usually carry just one or two people at a time, a bus can carry 50 or more, and a train in a large city may carry thousands.
Motorcycles had a fatality rate of 212 per billion passenger miles, by far the highest of all modes: “A motorcyclist who traveled 15 miles every day for a year, had an astonishing 1 in 860 chance of dying — 29 times the risk for automobiles and light trucks.”
Public transit is a vital force for the American economy. The American Public Transportation Association estimates that 87% of trips directly benefit the local economy, with $1 invested in public transit believed to generate $5 in economic returns.