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…