 An alternative airport site to Gardermoen was proposed at Hurum, south-west of Oslo.Had Hurum been chosen, the Gardermoen Line would not have been necessary for the airport express train, but the planning documents recommended that construction still proceed to ease traffic congestion north of Oslo.The tunnel is used by all trains on the Gardermoen Line, including the Flytoget airport express, and the regional and express trains which continue via the Dovre Line.