A report from 1982 recommended that construction be carried out in two phases. First a road departing from the E18 at Jessvoll near Drammen through Røyken and then under the fjord before terminating at an intersection with the E6. The second phase would see the construction of a road from the tunnel through Hurum to Verket, in a new subsea tunnel under the Drammensfjord near Svelvik and then through a tunnel to Sande, where it would intersect with the E18. Cost estimates for the tunnel ranged between NOK 200 and 360 million. The plans were based on partially using part of National Road 154 in Buskerud for part of the feeder road. Cost estimates for the auxiliary road system was estimated at between NOK 340 and 400 million, depending on the amount of reused road and the standard chosen.