Ryggedal Tunnel
The Ryggedal Tunnel (, also known as the Bø Tunnel, ) is a road tunnel that is part of Norwegian County Road 820 in the municipalities of Bø and Øksnes in Nordland county, Norway. The tunnel is long. Work on the tunnel was begun in 1977 under the leadership of the engineer Edward Pegg, and the tunnel was opened on October 17, 1980. Built at a cost of , this was the most expensive tunnel project in Norway until that time and also the most difficult. One-sixth of the tunnel has molded concrete vaulting. The tunnel and its road gave  the municipality of Bø a ferry-free road connection with the outside world, and it replaced the ferry crossings between Kråkberget in the municipality of Bø and Sandset in the municipality of Øksnes. Like many other tunnels in Norway, the Ryggedal Tunnel has condensation problems. Condensation can lead to dangerous situations because the pavement suddenly becomes damp when entering the tunnel. The tunnel's infrastructure was upgraded in 2015.