Public transport is transportation provided for use by the general public. These modes of transportation are usually managed on a schedule, have designated routes, and have a posted fee for each trip. Public transport within cities include buses, trams, metros, and ferries. Airlines, coaches, and intercity rails are common modes of public transport between cities; these modes of transportation between cities is also known as civil transport. Water transport, noted in ancient Greek mythology, was the earliest form of public transport. Geographical, historical and economic reasons dictate the use and extent of public transportation systems. Regardless, public transit is significantly more energy efficient than other modes of travel.