 When the new airport opened on 8 October 1998 the Flytoget airport express trains started operating immediately, as did the Gardermoen Line from Lillestrøm to the airport and onwards to Eidsvoll.Because the tunnel was not finished, trains were required to use the old Trunk Line from Oslo Central Station to Lillestrøm.After this diversion the express trains switched to the completed section of the new Gardermoen Line between Lillestrøm and Oslo Airport.