Transit is a service that carries large numbers of people from place to place within cities or between cities and their suburbs. Most large urban areas provide some such service, also called public transportation.
Buses are by far the most common transit vehicles. Most run on city streets and share the road with other traffic. These buses usually follow a fixed schedule, and they pick up and drop off passengers at designated stops. A typical city bus can carry up to about 70 people.
Other common transit systems include three types of rail transportation: (1) light rail, (2) subways and elevated systems, and (3) commuter rail.
Light rail trains consist of one to six electrically powered cars. Each car usually carries up to about 100 people. In the city center, the tracks are usually in the middle of the street. In less crowded areas of the city, and in the suburbs, the tracks are usually next to the street or on a separate right of way (strip of land reserved for a particular use).
Subways and elevated systems operate electrically powered trains that usually have from 1 to 10 cars. Each car can carry up to about 100 passengers. The trains run underground, on elevated tracks, or both.
Commuter rail systems operate trains over exclusive rights of way between cities and their suburbs. The trains carry most of their passengers during morning and evening rush hours. Many commuter trains use diesel-powered locomotives.
