Tvärbanan is a light-rail line in Stockholm, Sweden. Its name translates literally to The transverse line, as it operates crosswise to the otherwise radial metro and commuter rail lines of Stockholm. It links together several transit lines through its connections with the southern, western and northern subway branches of the Stockholm Metro (Tunnelbana) as well as three branches of the Stockholm commuter rail (Pendeltåg). The possibility to travel between southern, western and northern greater Stockholm without having to enter the city centre significantly reduces the number of transit passengers, also reducing the number of trains having to pass through the Old Town bottleneck during peak hours. Near Liljeholmen the track is shared with freight traffic for a short section, this being the only place in Sweden where freight traffic and trams share the same track.

The Stockholm Metro is a rapid transit system in Stockholm, Sweden. The first line opened in 1950 as the first metro line in the Nordic countries, and today the system has 100 stations in use, of which 47 are underground and 53 above ground. There are three coloured lines, as shown on the tube maps, which form seven numbered routes with different termini. Routes numbered 17, 18 and 19, 13 and 14 and 10 and 11 all go through the centre of the city, resulting in a very centralized system. All three lines and seven routes interchange at T-Centralen station. Apart from this, there are three other interchange between lines, at Fridhemsplan, Slussen and Gamla stan stations.