The works consist of upgrading/renovating 5 tunnels on the E6 in Sør-Trøndelag and Nord-Trondelag for the Norwegian Public Roads Administration, Mid Region. The 1st 4 tunnels are relatively close to each other between Trondheim in Sør-Trondelang and Stjørdal in Nord-Trøndelag; Grillstad tunnel (748 m), Være tunnel (1 625 m), Stavsjøfjell tunnel (1 720 m) and Hell tunnel (3 928 m). The fifth tunnel, Egge tunnel (597 m), is located just north of Steinkjer in Nord-Trøndelag.
Grillstad tunnel is dual carriageway, whilst the other tunnels are only single carriageway. The tunnels can be completely closed for traffic when work is being carried out in the tunnel. The tunnels can only be closed at night as well as on a certain number of weekends.
The works mainly consist of the delivery and installation of variable message signs and barriers, lighting, fire extinguishing equipment, safety equipment, fans, cable racks and TV surveillance. See the summary for the details on each tunnel in chapter A3 point 1.