Manchester Metrolink (branded locally simply as Metrolink) is a tram/light rail system in Greater Manchester, England. The network has 99 stops along 64 miles (103 km) of standard-gauge route, making it the most extensive light rail system in the United Kingdom. Metrolink is owned by the public body Transport for Greater Manchester (TfGM) and operated and maintained under contract by a Keolis/Amey consortium. In 2021/22, 26 million passenger journeys were made on the system. The network consists of eight lines which radiate from Manchester city centre to termini at Altrincham, Ashton-under-Lyne, Bury, East Didsbury, Eccles, Manchester Airport, Rochdale and Trafford Centre. It runs on a mixture of on-street track shared with other traffic; reserved track sections segregated from other traffic, and converted former railway lines. Metrolink is operated by a fleet of 147 high-floor Bombardier M5000 light rail vehicles. Each service runs to a 12-minute headway; stops with more than one service experience combined headways of 6 minutes or less. At the busiest times some services operate as 'doubles', with two vehicles coupled together. A light rail system for Greater Manchester emerged from the failure of the 1970s Picc-Vic tunnel scheme to obtain central government funding. A light-rail scheme was proposed in 1982 as the least expensive rail-based transport solution for Manchester city centre and the surrounding Greater Manchester metropolitan area. Government approval was granted in 1988, and the network began operating services between Bury Interchange and Victoria on 6 April 1992. Metrolink became the United Kingdom's first modern street-running rail system; the 1885-built Blackpool tramway being the only first-generation tram system in the UK that had survived up to Metrolink's creation. Expansion of Metrolink has been a critical strategy of transport planners in Greater Manchester, who have overseen its development in successive projects, known as Phases 1, 2, 3a, 3b, 2CC and Trafford Park. The latest extension, the Trafford Park Line from Pomona to the Trafford Centre, opened in March 2020. The Greater Manchester Combined Authority has proposed numerous further expansions of the network, including the addition of tram-train technology to extend Metrolink services onto local heavy-rail lines.