Metro Train

Metro is the most common term for underground rapid transit systems used by non-native English speakers.[14] 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,[15] underground,[16] Untergrundbahn (U-Bahn) in German,[17] or the Tunnelbana (T-bana) in Swedish;[18] the use of viaducts inspires names such as elevated (L or el), skytrain,[19] overhead, overground or Hochbahn in German. One of these terms may apply to an entire system, even if a large part of the network (for example, in outer suburbs) runs at ground level.

Rapid transit systems may be supplemented by other systems such as trolleybuses, regular buses, trams, or commuter rail. This combination of transit modes serves to offset certain limitations of rapid transit such as limited stops and long walking distances between outside access points. Bus or tram feeder systems transport people to rapid transit stops.[29]