Green public transportation involves the use of mass transit vehicles that have less of an environmental impact than traditional ones. This can be achieved through methods as relatively simple as using ethanol-based fuels in buses, or as complex as converting an entire urban transportation system to hydrogen-powered vehicles. The ultimate goal of establishing a green public transportation system is to have as little negative effect on the environment and landscape as possible. Although many steps have been taken around the world to help establish green systems, some areas are having more difficulty changing than others.
One step many public transportation systems are taking to reduce emissions is using alternative fuels in their buses. This is a practical measure that can have a positive effect on emissions over time. Even though the buses themselves will not increase their per-gallon mileage, they will release a smaller amount of harmful pollutants. Alternative fuels such as biodiesel and ethanol allow a city to keep its fleet of existing buses while taking steps to become greener.
Another effort that can have an effect on developing a green public transportation system is surface transportation planning. This involves looking at the effectiveness of different routes, eliminating redundancies and studying how the movement of public transportation affects other modes of transportation. Through a number of actions, such as modifying bus routes, adjusting the timing of traffic lights and changing how trains and subways make their stops, emissions can be reduced throughout a public transit system and reduce harmful vehicle idling.
The above methods of facilitating a green public transportation system are ways that do not involve radical changes to the existing infrastructure of an area. Ultimately, as new technologies advance, roads, rail lines and subways might need to be modified. This kind of construction gives a city the opportunity to incorporate new, green public transportation technology into everyday life.
Examples of new transit technologies include energy-efficient magnetic levitation trains, lightweight electric buses and other vehicles, and solar-powered train cars. Some new ideas also have started to pop up, such as the personal rapid transit system, in which small "pods" that seat very few people travel quickly along a network, allowing direct travel from point to point without multiple stops on the way. Many ideas have been proposed around the world, but the limitations of financing and the ability to effectively modify existing infrastructures can hinder widespread changes.
