Public transport in Brno consists of 12 tram lines (1 historic with old trams), 14 trolleybus lines (the largest trolleybus network in the Czech Republic) and almost 40-day and 11 night bus lines. Trams (often called "šaliny" by the locals) have a long tradition in Brno; they first appeared on the streets in 1869; this was the first operation of horse-drawn trams in the current Czech Republic. The local public transport system is interconnected with regional public transport in one integrated system called IDS JMK, and also directly connects several nearby municipalities with the city. Its main operator is the "DPmB" company (Brno City Transport Company) which also operates a ferry route, mainly recreational, at the Brno Dam Lake. There is a tourist minibus providing a brief tour of the city. In 2011, the city announced plans to build a metro system light rail system to alleviate overcrowding of trams and to reduce the congestion on the surface.