<P> In order to compare energy impact of public transportation to private transportation, the amount of energy per passenger mile must be calculated . The reason that comparing the energy expenditure per person is necessary is to normalize the data for easy comparison . Here, the units are in per 100 p - km (read as person kilometer or passenger kilometer). In terms of energy consumption, public transportation is better than individual transport in a personal vehicle . In England, bus and rail are popular methods of public transportation, especially London . Rail provides rapid movement into and out of the city of London while busing helps to provide transport within the city itself . As of 2006--2007, the total energy cost of London's trains was 15 kWh per 100 p - km, about 5 times better than a personal car . For busing in London, it was 32 kWh per 100 p - km, or about 2.5 times that of a personal car . This includes lighting, depots, inefficiencies due to capacity (i.e., the train or bus may not be operating at full capacity at all times), and other inefficiencies . Efficiencies of transport in Japan in 1999 were 68 kWh per 100 p - km for a personal car, 19 kWh per 100 p - km for a bus, 6 kWh per 100 p - km for rail, 51 kWh per 100 p - km for air, and 57 kWh per 100 p - km for sea . These numbers from either country can be used in energy comparison calculations or life cycle assessment calculations . </P> <P> Public transportation also provides an arena to test environmentally friendly fuel alternatives, such as hydrogen - powered vehicles . Swapping out materials to create lighter public transportation vehicles with the same or better performance will increase environmental friendliness of public transportation vehicles while maintaining current standards or improving them . Informing the public about the positive environmental effects of using public transportation in addition to pointing out the potential economic benefit is an important first step towards making a difference . </P> <P> Urban space is a precious commodity and public transport utilises it more efficiently than a car dominant society, allowing cities to be built more compactly than if they were dependent on automobile transport . If public transport planning is at the core of urban planning, it will also force cities to be built more compactly to create efficient feeds into the stations and stops of transport . This will at the same time allow the creation of centers around the hubs, serving passengers' daily commercial needs and public services . This approach significantly reduces urban sprawl . Public land planning for public transportation can be difficult but it is the State and Regional organizations that are responsible to planning and improving public transportation roads and routes . With public land prices booming, there must be a plan to using the land most efficiently for public transportation in order to create better transportation systems . Inefficient land use and poor planning leads to a decrease in accessibility to jobs, education, and health care . </P> <P> An important social role played by public transport is to ensure that all members of society are able to travel, not just those with a driving license and access to an automobile--which include groups such as the young, the old, the poor, those with medical conditions, and people banned from driving . Automobile dependency is a name given by policy makers to places where those without access to a private vehicle do not have access to independent mobility . </P>

Use of public transport to avoid pollution explanation