The city of Wuppertal in Germany is to benefit from refurbishment work to the Kiesberg road tunnel link. Measuring around 1km, the tunnel opened to traffic in 1970 following a five-year construction project. The link is of note as it was the first road tunnel in Europe to feature a dual-deck design, with two lanes of traffic in one direction on the upper deck and two lanes of traffic in the other direction on the lower deck.
The Kiesberg Tunnel links the Wuppertal-Sonneborn A46 Autobahn junction with the southern side of Wuppertal. The project is being managed by Strassen NRW. The upgrade work is one of several projects planned to improve transport infrastructure in Germany at present.
The tunnel has been in use for over 50 years but has issues with its structure and also with its safety equipment. The insufficient waterproofing means that the structure has issues with water penetration, moisture penetration, concrete and reinforcement damage as well as ice formation in winter. As the tunnel is damp permanently, this has also caused issues for the control cabinets, cables and technical systems.
The work involves sealing the tunnel from the outside using a foil seal and a new water-pressure-retaining inner shell, dismantling the floor in the lower tube and the ceiling slab between the upper and lower level and installing a new carriageway slab. It also includes a cross-section adjustment with one lane in each direction plus a narrow hard shoulder, in line with traffic forecasts as well as renewal of the lighting, ventilation, safety technology and control systems. Upgrading the ventilation will allow truck traffic again. Although the tunnel was designed to handle around 25,000 vehicles/day, forecasts expect it to handle 15,000 vehicles/day.
Other work will be carried out to bridges, portals, retaining walls, drainage and rainwater retention basins. The work will also include replacing the L 70 overpass over Viehhofstraße. The entire project is expected to take two years.
