Mass Transit

Mass transit, sometimes referred to as public transit or public transport, describes public and private systems that carry groups of people in a variety of vehicular configurations, called modes. Typical modes include the bus, rail rapid or heavy rail, commuter rail, light rail, and automated guideway systems. The bus, often powered by diesel fuel, typically operates in mixed traffic on city streets, although dedicated bus lanes are also found. Recent innovations include hybrid diesel-electric vehicles and technologies such as automatic vehicle location using global positioning systems (GPS), electronic fare collection, and traffic signal priority systems. Bus rapid transit (BRT) describes a system of vehicular, operational, and station improvements designed to reduce travel times and improve the trip experience.

Rail rapid (also called “heavy rail”) refers to high-capacity and high-speed systems operating on a dedicated right-of-way using third-rail electric power and self-powered cars. Examples include the New York City subway, Washington Metro, and London Underground. These systems are expensive to construct but have the greatest carrying capacity. For example, Washington Metro, which opened in 1976 and has more than 100 miles of track, cost approximately $10 billion. Commuter rail systems operate on dedicated or shared (with freight service) railways and often focus on connecting cities and suburbs. These trains may be pulled by electric or diesel engines, or they may be self-propelled.

Light rail transit (LRT) is the current evolution of the streetcar, tram, or trolley. These rail vehicles are lighter in weight than conventional rail cars and are self-propelled. LRT systems can run on city streets as well as on separate right-of-ways. Popular in Europe for decades, light rail is becoming popular in the United States, with more than 15 new systems installed since 1980. Most LRT systems run in two- to four-car trains and use overhead wire for electric service, eliminating the need for expensive at-ground third-rail power.

Automated guideway transit (AGT) refers to dri-verless and highly automated operations typically found in high activity centers that span long distances, such as airports. They operate on completely separate guideways, sometimes labeled “horizontal elevators.” Airports, such as Dallas-Fort Worth and Atlanta, have [Page 558]AGT systems. Vancouver, Canada, has the longest automated system in the world, Sky Train. This urban transit operation is more than 49 kilometers long with 33 stations.