The metro is often referred to as subway, underground or in the elevated version as light rail.

Metro | Underground | Subway | City Railway | Light Rail

The metro or light rail is the most powerful transport system for local public passenger transport, like city railways (suburban railway, metropolitan railway). The metro and light rail are transport systems on rails, which run autonomously, without any crossroads and independent from other city transport systems. Lately metros and elevated light rails are often built fully automated and with automated station platform doors.

Both, the metro, and light rail, are high performance systems for the local public passenger transport with train capacities of up to 1,000 passengers and a speed of up to 100 km/h. For small and middle-sized cities, they are not relevant as a backbone transportation system. Since the performance potential is so high, stations should not be too close to each other and have a minimum distance of 700 m so that the metro or light rail make full use of its potential.