Dublin once had an extensive system of trams but this was largely phased out by 1949. A new light rail system, often described as a tram system, the Luas, was launched in 2004, and is run by Transdev Ireland (under contract from Transport Infrastructure Ireland), carrying over 34 million passengers annually. The network consists of two interconnecting lines; the Red Line links the Docklands and city centre with the south-western suburbs of Tallaght and Saggart, while the Green Line connects northern inner city suburbs and the main city centre with suburbs to the south of the city including Sandyford and Brides Glen. Together these lines comprise a total 67 stations and  of track. Construction of a 6 km extension to the Green Line, bringing it into the north of the city, commenced in June 2013 and was opened for passenger travel on 9 December 2017.