The work comprises the renovation of Ekeberg and Svartdals tunnel on the E6/E18 in Oslo, in the eastern part of the Opera tunnel. The Ekeberg and Svartdals tunnel is 2 connected 2-course tunnels with 2, partly 3, lanes in each course, as well as extensions by ramps. The Ekeberg tunnel is 1 580 m and stretches from Sørenga to Lodalen. The Svartdals tunnel's eastbound and westbound courses are approx. 1 460 and 1 700 m respectively, measured from the Ekeberg tunnel to Ryen.
The work shall be carried out in one course at a time, mainly during nightly closures. Due to the restricted closure time, emphasis is put on the work being carried out as quickly as possible.