Light metro

Light metro, light rapid transit (LRT) or a medium-capacity system (MCS), is a rail transport system with a capacity greater than light rail, but less than rapid transit. It typically resembles a rapid transit system in terms of infrastructure, but typically features smaller rolling stock and stations, and may have a differing network topology. Since ridership determines the scale of a rapid transit system, statistical modeling allows planners to size the rail system for the needs of the area. When the predicted ridership falls between the service requirements of a light rail system and a rapid transit system, a light metro project is indicated. A light metro system may also result when a rapid transit system fails to achieve the requisite ridership due to network inadequacies (e.g. single-tracking) or changing demographics. In contrast with light rail systems, a light metro system runs on an entirely grade separated exclusive right of way, and is therefore completely separated from other traffic. In some cases, the distance between stations is much longer than typically found on rapid transit systems. A light metro system may also be suitable for branch line connections to another mode of a heavy-capacity transport system, such as an airport or a main route of a metro network. However, despite their smaller trains, some light metro systems can rival rapid transit networks in terms of capacity thanks to automatic train operation allowing extremely high-frequency service.