Blue line (Stockholm metro)

When the blue line was designed during the boom years of the 1960s, there were also plans to build an extension from Kungsträdgården to Nacka, but they were not realized. However, in 2013, it was decided that the line will run from Kungsträdgården to Nacka centrum via Sofia, Hammarby canal, Sickla and Järla. Construction was expected to have started in 2019 and completed seven to eight years later.[4][5] A new bus terminal will be built at Nacka centrum to relieve congestion at Slussen for services to different parts of Nacka and Värmdö municipalities.

The transportation review also included an extension from Sofia to Sockenplan, which would include transferring the Hagsätra branch from the Green line to the Blue. The route through the Slakthus area was finalised in May 2015, along with a new underground station to replace Globen and Enskede gård on the Green line. Construction started in 2019, and service is expected to begin in 2030.[4][5]

An extension beyond Akalla was approved for line 11. An intermediate station will serve the new Barkarbystaden residential area, and the line will terminate at the Stockholm commuter rail Barkarby station, allowing revisions to the commuter service. Official groundbreaking took place in September 2018, with completion now scheduled for 2026.[6]

In total, the Blue line has 20 stations, of which 19 are underground and one (Kista) is on the surface. The tunnel between Hjulsta and Kungsträdgården is the longest of the system at 14.3 kilometres (8.9 miles), and is also Sweden's longest tunnel. (However, metro tunnels are usually omitted from lists of the country's tunnels.) Although the Blue line is almost entirely in tunnel, it also has the metro's longest elevated section at Kista, 1,200 metres (3,900 ft) long.

The 11 busiest stations (by number of boardings on a winter weekday in 2018) are:[1]