hybrid between a light rail and a street tram with six lines, and the suburban line of Trondheim Tramway, the Gråkall Line. The Bergen Tramway was closed in 1965, but the new Bergen Light Rail opened in 2010. Poland Trams currently operate in 15 Polish cities: Bydgoszcz, Częstochowa, Elbląg, Gdańsk, Gorzów Wielkopolski, Upper Silesian Industrial Region, Grudziądz, Kraków, Łódź, Olsztyn , Poznań, Szczecin, Toruń, Warsaw and Wrocław. The largest system is in Upper Silesia with 255 km of track and 35 lines, followed by Warsaw with 150 km of route length and 34 lines and Łódź with 124 km of route length and 28 lines. A system in Płock was planned but the construction was postponed indefinitely in 2011. Portugal The Lisbon tramway network has been managed by the Companhia Carris de Ferro de Lisboa, or Carris for short, for over a century. Since 1995, the fleet includes authentic vintage cars, units made from vintage bodies powered by modern engines, and fully modern articulated trams. In Porto, a tram network has been in operation since 12 September 1895, making it the first electric tramway in the Iberian Peninsula. Many routes closed in the 1970s and 1980s, but one survived and some closed sections have reopened in the 2000s, and four routes are currently in operation. A heritage tram line operates seasonally in Sintra. Reductions in the network's original service started in 1954, until closure in 1975. It was re-opened in 1980 using a section of the former line and surviving trams. Almada has a light rail network, the Metro Sul do Tejo, which opened in 2007, following two decades of planning. Extensions to Seixal and Barreiro are currently planned. Romania There are currently 11 tram systems in Romania, in Arad, Botoşani, Brăila, Bucharest, Cluj-Napoca, Craiova, Galaţi, Iaşi, Oradea, Ploieşti, Timișoara. Serbia Belgrade has a large tram network with 12 lines on 127.3 km of track. The system is operated with around 250 units and with ČKD Tatra KT4 and Duewag Be 4/6 trams. The first horse-drawn tram line was introduced in October 1892 and the first electric one in 1894. There are long-term plans to build a new track to the Mirijevo neighbourhood, in the east of the city. Previously the cities of Niš, Novi Sad, and Subotica also had tram networks, but these closed in Novi Sad and Niš in the 1950s, and in Subotica in 1974. Slovakia There