List of metro systems

In some parts of the world, metro systems are referred to as subways, undergrounds, tubes, mass rapid transit (MRT), metrô or U-Bahn.

As of 2024,[update] the country with the most metro systems is China, with 54 in operation, including 11 of the 12 longest networks in the world.

The UITP only makes distinctions between "metros" and "light rail", whereas [6] the American Public Transportation Association (APTA) and Federal Transit Administration (FTA) distinguish all three modes.

While light rail systems may share roads with car traffic or use sections of track with level crossings across roads, metro systems tend to run on a grade-separated exclusive right-of-way with no access for other traffic.

Most metro systems do not share tracks with freight trains or inter-city rail services.

It is not relevant whether the system runs on steel wheels or rubber tyres, or if the power supply is from a third rail or overhead line.

Certain transit networks may match the service standards of metro systems, but reach far out of the city and are sometimes known as S-Bahn, suburban, regional or commuter rail.

This list expressly does not aim at representing the size and scope of the total rapid transit network of a certain city or metropolitan area.

The data in this list should not be used to infer the size of a city's, region's, or country's urban rail transit systems, or to establish a ranking.

The countries of Iraq, Mongolia, Israel, Ivory Coast and Serbia are currently constructing their first ever metro systems.

Simmons-Boardman Publishing Inc. Retrieved 8 December 2020.As for the latest extension, see "'CMRL likely to handle up to 3.5L daily commuters soon'".

Retrieved 6 April 2020.As for the latest extension, see "La Comunidad abre la estación de metro Arroyofresno al público tras 20 años" [The Community of Madrid opens Arroyofresno metro station to the public after 20 years].