A key rail tunnel connecting Oslo and Lillestrøm will be closed for six weeks this summer due to upgrade work. The closure of Romeriksporten tunnel will significantly impact train services, affecting both the Gardermoen railway line and the Flytoget airport express train. Passengers should expect disruptions and potential delays during the maintenance period. The upgrade aims to improve infrastructure and ensure the long-term reliability of the rail network. Authorities have not yet detailed specific alternative transport arrangements for commuters. The closure is scheduled to take place throughout the summer months, a peak travel season. Further information regarding revised timetables and travel options will be released closer to the start date.