# Timeline of transport in Oslo

Timeline of transport in Oslo covers key incidents within transport in Oslo, the capital of Norway.
The first railway opened in 1854, the first horsecar tramway in 1875 and the rapid transit system in 1966.
| Year | Date | Event |
| 1854 | September 1 | Hoved Line, Norway's first railway from Oslo Ø to Eidsvoll opened. |
| 1872 | October 7 | The Drammen Line and Oslo Vestbanestasjon opened. |
| 1874 | August 26 | Kristiania Sporveisselskap established. |
| 1875 | October 10 | The first horsecar line opened, from Homansbyen and Vestbanen via Stortovet to Oslo and Grünerløkka. |
| 1878 | December 2 | The tram line to Oslo extended to St. Hallvards plass. |
| 1879 | January 2 | The Østfold Line opened to Halden. |
| 1879 | April 12 | The Grünerløkka Line extended to Bayerbrua. |
| 1879 | May 5 | The tram line to Vestbanen extended to Munkedamsveien. |
| 1894 | March 3 | Kristiania Elektriske Sporvei started operations with an electric tram line from Østbanen via Briskeby to Majorstuen, as well as a branch line from Parkveien to Skillebekk. |
| 1894 | December 31 | The Skillebekk Line (today the Skøyen Line) extended to Nobels gate. |
| 1898 | May 31 | The Holmenkoll Line opened from Besserud to Majorstuen. |
| 1899 | November 24 | Kristiania Kommunale Sporveie opened their first tram line, to Sagene. |
| 1900 | January 15 | Electrification of the tram lines concluded. |
| 1900 | March 27 | The tram line to Rodeløkka opened. |
| 1900 | August 28 | The tram line from Tollbugata to Festningsbryggen opened. |
| 1900 | December 12 | The North Line, later renamed Gjøvik Line, opened from Grefsen to Jaren. |
| 1901 | January 20 | The Alnabru–Grefsen Line opened. |
| 1901 | | The Skillebekk Line extended to Thune. |
| 1902 | November 28 | The North Line extended from Grefsen to Oslo Ø. |
| 1902 | November 28 | The Grünerløkka Line extended to Grefsen. |
| 1902 | | The Frogner Line opened from Østbanen to Frogner Plass. |
| 1903 | June 21 | The Skøyen Line extended to Skøyen. |
| 1903 | October 1 | Lillestrøm–Bryn on the Hoved Line rebuilt to double track. |
| 1904 | September 1 | Bryn – Oslo Ø rebuilt to double track. |
| 1905 | | Kristiania Kommunale Sporveie taken over by Kristania Sporveisselskab. |
| 1907 | May 1 | Loenga–Alnabru Line opened. |
| 1907 | November 13 | Oslo Port Line opened, connecting Oslo Ø with Oslo V. |
| 1909 | | Tram lines start being numbered. |
| 1912 | November 7 | The Smestad Line opened to Smestad. |
| 1914 | May 15 | The Frogner Line extended to Majorstuen. |
| 1916 | May 16 | The Holmenkoll Line extended to Tryvann. |
| 1917 | June 11 | The Ekeberg Line opened to Sæter. |
| 1917 | | The municipal owned AS Akersbanrene established. |
| 1919 | May 9 | The suburban Lilleaker Line opened from Skøyen to Lilleaker. |
| 1922 | November 26 | Oslo V – Sandvika on the Drammen Line rebuilt to double track and electrified. |
| 1923 | December 18 | The Østensjø Line opened from Vålerenga to Bryn. |
| 1924 | January 1 | The Municipality of Oslo takes over the running of the two streetcar companies, creating Kristiania Sporveier. |
| 1924 | June 1 | Bekkelaget–Ljan rebuilt to double track. |
| 1924 | July 1 | The Lilleaker Line extended to Bekkestua. |
| 1924 | November 2 | The Lilleaker Line extended to Haslum. |
| 1924 | | AS Ekebergbanen starts operating the first bus lines. |
| 1925 | January 1 | Kristiania changed its name to Oslo, and Kristiania Sporveier its name to Oslo Sporveier. |
| 1926 | January 10 | The Østensjø Line extended to Oppsal. |
| 1927 | September 1 | The Hoved Line electrified. |
| 1927 | | Oslo Sporveier starts bus operations. |
| 1928 | June 27 | The Holmenkoll Line is extended to the underground Nationaltheatret as the first Nordic underground railway. |
| 1928 | October 15 | Loenga–Alnabru electrified. |
| 1929 | May 15 | Oslø Ø – Bekkelaget rebuilt to double track. |
| 1930 | January 1 | The Lilleaker Line extended to Kolsås. |
| 1931 | September 30 | The Simensbråten Line opened, branching off from the Ekeberg Line at Jomfrubråten to Simensbråten. |
| 1934 | October 10 | The Sognsvann Line opened. |
| 1935 | January 24 | The Smestad Line extended to Røa, and changes name to the Røa Line. |
| 1936 | December 9 | Oslo Ø – Ljan electrified. |
| 1936 | December 15 | Ljan–Kolbotn rebuilt to double track. |
| 1937 | January 4 | The Østensjø Line taken over by AS Bærumsbanen. |
| 1937 | January 18 | Ljan–Kolbotn electrified. |
| 1940 | December 17 | The first line of the Oslo trolleybus opened. |
| 1941 | September 17 | The Ekeberg Line extended to Ljabru. |
| 1942 | June 15 | The Kolsås Line trams reroute via Majorstuen to Nationaltheatret, with the opening of the Kolsås Line from Jar to Smestad. |
| 1948 | | The municipalities of Oslo and Aker merge. |
| 1948 | December 22 | The Røa Line extended to Grini. |
| 1949 | January 17 | The Kongsvoll Line closed. |
| 1949 | February 6 | The Rodeløkka Line closed. |
| 1951 | December 3 | The Røa Line extended to Lijordet. |
| 1954 | | The city council decides to build the Oslo T-bane rapid transit. |
| 1955 | January 2 | A new line to Rodeløkka opened. |
| 1957 | April 28 | The Lambertseter Line opened. |
| 1957 | November 3 | A tram line connection between Grefsen and Sinsen opened. |
| 1958 | July 20 | The Østensjø Line extended to Bøler. |
| 1958 | July 20 | The tram network was at its greatest extent. |
| 1960 | October 30 | The Ekeberg Line moved from Grønland to Schweigaards gate. |
| 1960 | | The city council decides to terminate the trolleybus and tram services, and replace them with rapid transit and diesel buses. |
| 1961 | February 1 | Oslo Ø – Tøyen rebuilt to double track. |
| 1961 | February 1 | Oslo Ø – Jaren electrified. |
| 1961 | April 23 | The Rodeløkka Line closed. |
| 1961 | November 12 | The first trolleybus line closes. |
| 1962 | May 27 | Tøyen–Grefsen rebuilt to double track. |
| 1966 | May 22 | The Oslo Metro opened with the Lambertseter Line converted to rapid transit. |
| 1966 | October 16 | The Grorud Line to Grorud opened as part of the metro. |
| 1967 | October 29 | The Østensjø Line became part of the metro. |
| 1967 | October 29 | The Simensbråten Line closed. |
| 1967 | November 26 | The Østensjø Line extended to Skullerud. |
| 1968 | June 24 | The official closing of the trolleybus service. |
| 1970 | November 18 | The Furuset Line opened as part of the metro to Haugerud. |
| 1972 | November 16 | The Røa Line extended to Østerås. |
| 1974 | March 3 | The Grorud Line extended to Rommen. |
| 1974 | June 26 | Stor-Oslo Lokaltrafikk established to manage bus routes in Akershus, and from Akershus to Oslo. |
| 1974 | August 18 | The Grorud Line extended to Stovner. |
| 1974 | December 15 | The Furuset Line extended to Trosterud. |
| 1974 | | The last conductor on trams taken out of service. |
| 1975 | December 21 | The Grorud Line extended to Vestli. |
| 1977 | January 9 | The metro extended from Jernbanetorget to Sentrum. |
| 1977 | | The city council canceled the decision to close the tram lines. |
| 1978 | February 19 | The Furuset Line extended to Furuset. |
| 1980 | June 1 | The Oslo Tunnel opened. |
| 1981 | November 8 | The Furuset Line extended to Ellingsrudåsen. |
| 1981 | | First articulated buses into service. |
| 1982 | | The SL79 articulated trams put into service. |
| 1983 | March 20 | The metro line from Jernbanetorget to Sentrum closes due to leaks. |
| 1983 | | The Port Line closed. |
| 1986 | | Night buses entered service. |
| 1987 | March 7 | The Common Tunnel opens form Jernbanetorget to Nationaltheatret. |
| 1989 | May 28 | Oslo Vestbanestasjon closed. |
| 1989 | | Ticket machines enter service, with nine T-bane stations unmanned. |
| 1991 | | First bus lines subject to public service obligation. |
| 1993 | | The first through T-bane route, connecting the Sognsvann Line with the Lambertseter Line. |
| 1995 | | The Røa Line becomes a through service with the eastern T-bane lines. |
| 1995 | | The Vika Line tram opened. |
| 1995 | | T2000 multiple units into service on the T-bane. |
| 1997 | November 24 | The Østensjø Line extended to Mortensrud. |
| 1998 | January 5 | The Oslo Bus Terminal opened. |
| 1998 | October 8 | The Gardermoen Line opened. |
| 1999 | June 1 | The Ullevål Hageby Line extended to Rikshospitalet. |
| 1999 | August 22 | Romerike Tunnel opened. |
| 1999 | December 16 | Nationaltheatret Station rebuilt to four platforms. |
| 2000 | | SL95 trams into service. |
| 2002 | | Student discount introduced on public transport. |
| 2003 | July 1 | Oslo Sporvognsdrift and Oslo T-banedrift took over operation of the trams and T-bane. |
| 2003 | August 20 | The Ring Line opened to Storo. |
| 2006 | January 25 | MX3000 multiple units into service on the T-bane. |
| 2006 | July 1 | Oslo Sporveier split into Oslo Public Transport Administration and Kollektivtransportproduksjon. |
| 2006 | August 20 | The Circle Line opened from Storo via Sinsen til Carl Berners Plass. |
| 2008 | January 1 | Ruter took over as public transport administrator in Oslo and Akershus. |
| 2010 | December 6 | Holmenkollen line partially converted to metro standard, Holmenkollen station rebuilt to accommodate 6-car trains. |
| 2011 | August 17 | Kolsås Line Bekkestua station opened as a part of the renovation of the Kolsås Line. |
| 2012 | October 8 | Kolsås Line Gjønnes station re-opened after renovation. |
| 2013 | December 15 | Kolsås Line Haslum and Avløs stations re-opened, making Avløs the terminus of the Kolsås Line. The line is extended by bus to Kolsås. Bus 142 from Bekkestua now starts and terminates each travel on Kolsås, looping at Avløs. |