The assignment apply to an execution contract for the renovation and upgrading of the Follo Tunnel at E6 (the European road 6) in Akershus. The Follo tunnel shall comply with the Tunnel safety regulations when the renovation is completed. In addition various improvement measures shall be carried out in accordance with HB N500 Road Tunnels (Previously HB 021).

The Follo tunnel was opened in 1998 and is 903 m long. The existing tunnel cross section consists of 2 T9 profiles.

The works in the tunnel and in open air zones at E6 shall be executed during nights. When the work is executed in 1 of the tunnel lanes, this lane will be closed for traffic and 2 way traffic will be established in the second lane. Works in the open air zone at E6 shall also be executed during nights. This will require work notification, which is the builder's responsibility to issue. The need for a work notification is to be sent to the builder 14 days at the latest, before the work shall commence. Both tunnel courses shall be open for traffic during the daytime. Daytime is defined as the period between 5:30 and 22:00.

In connection with the renovation of the tunnel, measures shall also be carried out in the open air zones to the north and south of the Follo tunnel. The work will be carried out from profile no. -3000 to profile no. 12550.

It shall i.a. be installed signposts, pylons, technical buildings and trenches.

2 arches in the tunnel shall be removed in order to secure underlying rock. Removal of rock for a new technical room, the rock shall be removed by wire saw cutting. Bases are defect (at 75 sections) and these must be repaired.

Fire barriers shall also be installed between rock and concrete arches, as well as expansions of existing wall elements (SOS kiosks).