The Østensjø Line is a 9.0-kilometre (5.6 mi) line on the Oslo Metro which runs from Brynseng to Mortensrud. It further shares track with the Lambertseter Line along the 2.5-kilometre (1.6 mi) section from Tøyen to Brynseng. The line runs through the primary residential areas of Bøler, Østensjø and Søndre Nordstrand. The line is served by Line 3 of the metro.

The Grorud Line is a 13.0-kilometer long (8.1 mi) line on the Oslo Metro between Tøyen and Vestli in Oslo, Norway. Built as a mix of underground, at ground level and as an elevated line, it runs through the northern part of Groruddalen, serving such neighborhoods as Grorud, Romsås and Stovner. Line 5 runs along the entire line four times per hour. Line 4 runs between Vestli and Økern before branching off on the Løren Line to get onto the Ring Line. With 40,000 daily riders, the Grorud Line is the busiest branch of the metro.