Freiburg City Tunnel – Coordinated utility line planning

Freiburg City Tunnel – Coordinated utility line planning

In the course of constructing the A 860 highway, the German federal highway company is planning a “city tunnel with a full junction” in the inner-city of Freiburg. The necessary clearing of the construction site for the tunnel works requires the relocation of a wide variety of supply and disposal utility lines, especially in the areas of the open excavation pits for the two tunnel portals. For site clearance, we are providing the baseline assessment, preliminary design and basic design for the utility lines and aligning them with the tunnel structure, surface engineering and other factors as part of coordinated utility line planning. The designs are made three-dimensionally by various BIM authors as discipline-specific models and are overlaid with the digitized existing utility lines, the tunnel structure model and the digital terrain models (existing and planned surface) parallel to each other as well within a coordination model.

Project data:

  • About 12 km of inner-city utility line construction (sanitary/combined wastewater/stormwater sewers, drinking water supply, gas supply, cable routes)
  • About 50 individual works
  • Pipe diameters from DN 50 to DN 2,200
  • Above-ground and underground laying; cut-and-cover and trenchless construction methods
  • Depths from approx. 10 m below ground level to approx. 10 m above ground level


  • Feasibility study
  • Engineering structures §43 HOAI
  • Coordinated pipeline planning
  • Acoustic investigation
  • Traffic investigation
  • Public relations
  • Basic evaluation HOAI Ph. 1
  • Preliminary planning HOAI Ph. 2
  • Draft planning HOAI Ph. 3


  • 01/2018 - 08/2024

Investment costs:

  • About EUR 35 million preliminary construction costs (utility line construction)


The Autobahn GmbH of the Federal Government, Southwest Branch, Freiburg Field Office