The Vestfold Line (Vestfoldbanen) is a Norwegian railway line which runs from Drammen, through a number of towns in Vestfold and ending in the town of Skien in Telemark. At Skien, the line continues as the Bratsberg Line to Notodden. Service is provided by Norges Statsbaner with their InterCity Express service.
Vestfoldbanen has had many branch lines. The first opened in 1881 from Skoppum to Horten, and named the Horten Line. In 1895 the line from Eidanger to Brevik, the Brevik Line, was opened. In 1901, Tønsberg–Eidsfoss Line between Tønsberg and Eidsfoss. The following year, in 1902, Holmestrand–Vittingfoss Line opened between Holmestrand and Vittingfoss. The latter two branch lines were abandoned in 1938. The Brevik Line was closed for passenger traffic in the 1960s, and completely abandoned in the 1980s with part of the tracks removed. The line Porsgrunn–Norcem Cement Factory is still used for freight trains.
In 2004 much of the service between Larvik and Skien was curtailed, leaving only peak-hour departures on that stretch. This part of the line is somewhat tortuous, and there have been plans for a tunnel, Eidanger Tunnel, to shorten this leg.
The upgrades will allow speeds up to 200 km/h between stations, double track between Drammen and Larvik, and single track with two crossing loops from Larvik to Porsgrunn. The plans are to build lines in shorter stretches, allowing a steady increase in capacity. After completion, total travel time from Oslo to Tønsberg will be one hour (half an hour shorter than today), and travel time to Grenland will be reduced by about one hour. Some of the time reduction also comes from the construction of the Asker Line just west of Oslo.
The expansion of the line started in 1993, and in 1995 a four kilometers past Skoger was modernized. In 2001, 13 km through Sande was upgraded. 2002 saw the opening of a new crossing loop at Nykirke. This plan prioritizes parts north of Tønsberg as well as cutting times significantly between Larvik and Porsgrunn, where the line takes a long trip around, and will reduce travel time from 34 to 12 minutes. Current approved political plans include four new stretches to be completed before 2015: