Saint Petersburg is Russia's second largest city after the capital Moscow with almost 5 million inhabitants. Until the beginning of the 21st century, it had the largest tram network in the world, with almost 300 kilometres in length. After numerous route closures, it is still one of the Top 5 worldwide with a length of some 230 kilometres. The track gauge is 1.524 mm as usual in Russia. Although the network consists of two subnetworks, it is connected by non-revenue routes. In addition, the city has an almost 120-kilometre-long Metro network. The Metro stations rank among the most elegant in the world. Due to the city's special geology, the metro runs very deeply (mostly 70-100 meters).
The trams and trolleybuses are operated by a municipal company named Gorelektrotrans (Горэлектротранс), the metro is operated by "Peterburgski Metropoliten" (Петербургский Метрополитен).