The tunnel is indefinitely closed for vehicles exceeding in length. From the onset it was designed to be expanded to two tubes, hence a second tube was designed to be built on the south side. European Road 134 is long and runs from Haugesund through Drammen to the E6 at Vassum in Frogn. The section from Bjørnstad in Røyken to Vassum was built at the same time as the tunnel and is referred to as the Oslofjord Link (Norwegian: ). The crossing primarily serves as a quicker link connecting Buskerud to Follo and Østfold. Alternative crossing involve driving north via Oslo or south via the Moss–Horten Ferry. The route saves and 30 minutes compared to driving via Oslo.