Surveys of traffic patterns on Bømlo were undertaken by Vestland Public Roads Administration in 1984. Based on it and other feedback, the agency stated that it preferred a pontoon bridge between Foldrøyholmen and Sørstokken, north of the ferry between Bømlo and Stord. It was estimated to cost NOK 190 million, in addition to auxiliary roads for NOK 40 million. In 1982, plans were launched for a fixed link to the mainland further south, which would include a bridge over Digernessundet, a causeway and low bridge across Spissøysundet and a low bridge over Gassasundet. In addition, a tunnel would have to be built from Føyno to Sveio. This proposal was similar to the finalized Triangle Link. In 1985, an all-tunnel proposal, following the same route, was proposed. Hordaland Public Roads Administration stated that the proposals were unrealistic. The limited company Ytre Sunnhordland Bru- og Tunnelselskap AS (SBT) was founded in October 1986 by the municipalities of Bømlo, Stord, Fitjar and Sveio, Hordaland County Municipality and five banks.