Rapid transit systems may be named after the medium by which passengers travel in busy central business districts the use of tunnels inspires names such as subway, underground, Untergrundbahn ( U-Bahn) in German, or the Tunnelbana (T-bana) in Swedish. The term Metro is the most commonly used term for underground rapid transit systems used by non-native English speakers. The three busiest rapid transit systems in the world by annual ridership are the Shanghai Metro, Tokyo subway system and the Moscow Metro. The world's largest single rapid transit service provider by number of stations (472 stations in total) is the New York City Subway. The world's longest single-operator rapid transit system by route length is the Shanghai Metro. In 1868, New York opened the elevated West Side and Yonkers Patent Railway, initially a cable-hauled line using static steam engines.Īs of 2021, China has the largest number of rapid transit systems in the world-40 in number, running on over 4,500 km (2,800 mi) of track-and was responsible for most of the world's rapid-transit expansion in the 2010s. The world's first rapid transit system was the partially underground Metropolitan Railway which opened in 1863 using steam locomotives, and now forms part of the London Underground. Some rapid transit systems have at-grade intersections between a rapid transit line and a road or between two rapid transit lines. They are typically integrated with other public transport and often operated by the same public transport authorities.

The stations typically have high platforms, without steps inside the trains, requiring custom-made trains in order to minimize gaps between train and platform. Some systems use guided rubber tires, magnetic levitation ( maglev), or monorail. Modern services on rapid transit systems are provided on designated lines between stations typically using electric multiple units on rail tracks. They are often grade-separated in tunnels or on elevated railways. Unlike buses or trams, rapid transit systems are railways, usually electric, that operate on an exclusive right-of-way, which cannot be accessed by pedestrians or other vehicles. A rapid transit system that primarily or traditionally runs below the surface may be called a subway, tube, or underground. Rapid transit or mass rapid transit ( MRT), also known as heavy rail or metro, is a type of high-capacity public transport that is generally found in urban areas. Countries shown in yellow have at least one metro system under construction. Countries shown in green have at least one operational metro system.

Rapidtransit masstransit