[1] Located at 313.2 meters (1,028 ft) above mean sea level, Roa has the highest elevation on the whole line.

[3] The line then runs south-west, past Bergerfoss and Kistefoss, before reaching Viul.

[2] At Hval, located 27 kilometers (17 mi) from Roa, there was formerly a spur to a military camp.

Just before reaching Hønefoss Station, the line runs on a 216-meter-long (709 ft) bridge over Begna.

During the 1880s and 1890s, all lines that did not connect to Sweden were to be built with 1,067 mm (3 ft 6 in) narrow gauge.

[8] At the time the line opened, there were stations at Roa, Grindvoll, Jevnaker, Hval and Hønefoss.

[2] To begin with, the line had a single through train from Oslo to Bergen, with an additional summer express—with a limited number of stops.

[2] Because of economic impact of World War I, the night train services was reduced to only twice a week from 20 May 1917 until 7 June 1919.

From 2 January to 1 May 1947, there was four weekly express services from Oslo to Geilo on the Bergen Line.

[13] By 1950, the situation had normalized and there were daily day and night trains and three weekly express trains—the latter with no stops between Hønefoss and Oslo.

The sections Oslo–Jaren and Roa–Hønefoss opened with 15 kV  16.7 Hz AC electric traction on 1 February 1961.

From 1989, this was reduced to a single round trip, with a morning train from Hønefoss to Oslo and a return in the afternoon.