Zoning plan | Ill.: Multiconsult


Junction area at Verpen | 3D model: Multiconsult/Vianova


Junction area at Måna | 3D model: Multiconsult/Vianova

National Road 23 (the “Oslofjord Link”)

Project phase 2, zoning plan and impact assessment, detailed design

As part of a consortium of consulting firms including Dr. Ing. A. Aas-Jakobsen AS and Vianova, Multiconsult was tasked with producing the zoning plan, detailed development plan and detailed design drawings for phase 2 of National Road 23, also known as the “Oslofjord Link”. This road section is approximately 14 km long, with 4 km in Hurum in Buskerud and 10 km in Frogn in Akershus.

The project involves building a second tunnel under the fjord in Oslo parallel to the existing one and upgrading the Måna-Vassum section of the road to dual carriageway, including adding second tunnels at Frogn and Vassum. The project also includes three grade-separated junctions along the section in question, as well as a new pedestrian and cycle path along Osloveien, which will carry diverted traffic. The new Route 23 has been designed with a central reservation, two overpasses and four bridges.

The upgrade is necessary to deal with traffic levels and due to new safety requirements in the Norwegian regulations on tunnels.

Scope of work

Drawing up zoning plans, including impact assessments, as well as detailed design.

Designing a new dual carriageway beside the existing road including a new tunnel under the fjord, bridges, overpasses, tunnel entrances, grade-separated junctions, landfill, noise mitigation, extensive investigation of soil conditions overground, underwater and in tunnels, geotechnical assessments, landscaping, vegetation buffers, water and wastewater systems and lighting.

Our services

  • Detailed Development Plan
  • Zoning plan including impact assessments
  • Geotechnical investigations
  • Technical reports and notes
  • 3D model of landscapes as input for interdisciplinary model
  • Detailed design