Construction of the railway started on 1 August 1994. Gardermoen is located about north of Oslo, but is not located on the Hoved Line. A different right-of-way had to be chosen north of Kløfta. The Hoved Line has heavy traffic, with many small stops until Lillestrøm, and continues northwards from Lillestrøm as single track. Therefore, an all-new railway would have to be built; it would bypass the intermediate railway until Lillestrøm, running through a tunnel, and continue northwards to the airport and onwards to Eidsvoll. This northernmost part is used to allow trains operating on the Dovre Line to Lillehammer and Trondheim to use the Gardermoen Line.