List of rapid transit systems



This is a list of rapid transit systems around the world. Such systems are commonly called metros, subways, elevated railways, rapid rail, or underground railways. The list is ordered by continent, country and city, and the systems are listed along with their opening year, system length and number of stations.

Considerations
There is no single and unambiguous definition of a rapid transit system, but the term often refers to systems that are called metro, subway or underground. Whereas the words subway and underground indicate that the system is sub-surface, the terms metro and rapid transit typically also include systems that are elevated or at surface level. A popular definition of metro is urban, electric passenger transportation system with high capacity and high frequency of service, which is totally independent from other traffic, road or pedestrians. The terms heavy rail (mainly in North America) and heavy urban rail have similar definitions.

The dividing line between rapid transit and other modes of public transport, such as light rail and commuter rail, is not always clear. A common way to distinguish rapid transit systems from light rail is by their separation from other traffic. While light rail systems may share roads or have level crossings, a rapid transit system runs on a grade-separated exclusive right-of-way, with no access for pedestrians and other traffic. And in contrast to commuter rail, rapid transit systems are primarily used for transport within a city, and have higher service frequency, typically not more than 10 minutes between trains during normal daytime service. Furthermore, rapid transit systems do not share tracks with freight trains or inter-city rail services. It is however not relevant whether the system runs on steel wheels or rubber tyres, or if the power supply is from a third rail or overhead lines.

The name of the system is not a criterion for inclusion. Some cities use rapid transit or metro as a brand name for a transit line with no component of rapid transit whatsoever. Similarly, there are systems branded light rail that meet every criteria for being a rapid transit system. Some systems also incorporate light metro or light rail lines as part of the larger system under a common name. These are listed, but the light rail lines are not counted for in the provided network data. Certain transit networks match the technical level and service standards of rapid transit, but reach far out of the city and are commonly known or better described as regional or commuter rail. These are not included. Neither are monorail and funicular systems, nor people movers, such as amusement park, ski resort and airport transportation systems.