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Definition: rapid transit from Dictionary of Energy

Transportation. 1. a system of urban public transportation using an electrically powered railway running along a separated right-of-way, which may be either below ground, elevated, or at grade. 2. a term for public transportation systems in general.


Summary Article: Public Transportation
From Green Consumerism: An A-to-Z Guide

Larger cities tend to have heavy-rail commuter service, like this elevated train in Chicago's Loop neighborhood.

Credit: iStockphoto

Public transportation refers to modes of transit that are available for use by the general public and that multiple people can use at once. Public transportation is most often contrasted with modes of transit that individuals can use, mostly commonly the automobile. Public transportation may include the use of buses, subways, heavy and light rail, and in some countries, ferries. In general, transportation options that are for hire, such as taxi services, are not considered public transportation, but other public operations such as vanpool services and services for the elderly or individuals with disabilities are considered public transit. Many of these services are subsidized by national, regional, and local governments, and as such have come to be considered a public good. Although there are many reasons individuals choose to use public transportation options, a recent trend is to do so to be green or to decrease one's carbon footprint.

The growth of the highway and road systems in the last decades caused more and more individuals to become increasingly dependent on transportation to get to work, entertainment activities, and shopping. Approximately 80 percent of the eligible population in the United States chooses to drive a car, or at least to obtain a driver's license. The history of individuals' reliance on personal transportation starts in 1916, when Congress created the Bureau of Public Roads and began matching funds with states for highway development. The Federal Highway Act of 1956 included earmarked revenue from a gasoline tax to provide funding for highway development that could be passed to the states. As a result, most state and local governments began to construct highways and roads.

Although the growth of the highway system resulted in many benefits for U.S. citizens, such as convenience of travel and the ability to pursue the “American Dream” of owning a house in the suburbs with a white picket fence, there were also a number of negative consequences associated with this trend. Some of these include the decentralization of cities, the high cost of road and highway maintenance for state and local governments, and an increase in the number of vehicle accidents. There were also environmental consequences, including the relationship between transportation and air quality—the most obvious indication of which was the creation of smog from vehicle emissions.

Individual vehicles are often singled out as examples of pollution creation. A number of countries and large cities monitor vehicle emissions in an attempt to control smog. In reality, emissions from automobiles are relatively minimal when compared with those of industrial polluters. It does remain the case, however, that cars are the largest single polluter because of the mass of vehicles in large metropolitan areas, in which emissions from individual automobiles add up. Pollutants from vehicles include hydrocarbons, nitrogen oxides, carbon monoxide, and carbon dioxide. Although other transit options also emit pollutants, the joint uses of these vehicles decrease the overall effect. Some studies suggest that public transportation in the United States uses approximately a little more that half the fuel required by automobiles. Some environmentalists also argue that individual automobiles emit more carbon monoxide, carbon dioxide, and nitrogen oxide than public transit options per mile.

As noted above, there are many different types of public transportation. The one most familiar to individuals in small to medium cities is bus service. A bus can transport numerous passengers, and differing bus routes can increase or decrease service based on demand. Buses use the road and highway system that is already in place and do not require much additional infrastructure. Larger cities tend to have heavy rail commuter service and/or light rail service in addition to bus service. Trains can transport more individuals than buses can, but they do require track infrastructure and stations. Many extremely large cities—mostly overseas—have also moved toward rapid transit systems. A rapid transit system includes electric passenger railways with designated service lines. Rapid transit systems usually move fewer people at once than traditional heavy or light rail but may travel at a faster pace.

As noted earlier, federal, state, and local governments often need to subsidize public transportation. As a public good, governmental entities may want to provide transportation for people who are unable to transport themselves for financial, physical, or legal reasons. Local governments may also wish to promote business and economic growth in urban centers by making transportation convenient. Transportation usually is one of the major budget items for state and local governments. A number of local and regional authorities in the United States and abroad are seeking to make public transportation more energy efficient and nonpolluting by such measures as careful transportation planning and routing, using hybrid fuels, developing efficient rapid and light rail transport systems, and using trolley buses or electrical rail systems based on renewable energies.

Individuals choose to use public transportation for a variety of reasons, from personal convenience to an effort to save money on fuel. Regardless of motive, however, there are environmental benefits from a decrease in the amount of automobile emissions.

See Also:

Automobiles, Carbon Emissions, Kyoto Protocol

Further Readings
  • Hanson, S. and Giuliano, G. The Geography of Urban Transportation. New York: Guilford, 2004.
  • Kutz, M. Environmentally Conscious Transportation. Hoboken, NJ: John Wiley & Sons, 2008.
  • U.S. Department of Transportation and U.S. Bureau of Transportation Statistics. National Transportation Library. Washington, D.C.: U.S. Department of Transportation, 1997.
  • Arney, Jo
    University of Wisconsin-La Crosse
    Copyright © 2010 by SAGE Publications, Inc.

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