To relieve traffic pressure on the center of the city of Lucerne of traffic, a new autobahn tunnel in the direction of Kriens is supposed to be constructed in the west of the city. At the southern entrance, the today four-lane Grosshof Bridge will be expanded to eight lanes. Based on the conviction that such a large and expensive structure should be used not only for traffic, out team came up with a multifunctional building with an autobahn in the intermediate story and a rooftop park with a spectacular view of the Pilatus and the alpine panorama.

As a building, the new bridge grows out of the slope of the Sonnenberg, spans Luzernerstrasse, is intercepted on the opposite side by the topography of the autobahn access, and flows into the valley landscape that follows to the south. A gate situation that is not staged, but is instead an integral component of the near-natural landscape is thus created between the Sonnenberg and the expanded Salesiahügel (Salesia hill). The infrastructure structure is supposed to be read as such, but nonetheless react to the urban planning conditions in a differentiated way at the same time. Conceived as a “bridge house” toward the city side and merging with the landscape toward the open valley side, the new Grosshof Bridge mediates between what exists and the new on all levels and becomes a vibrant urban landscape.

On the side of the Sonnenberg, the rooftop landscape is connected with the existing system of paths and thus produces a link with the autobahn park that adjoins to the south. The design is kept simple and reserved; species-rich meadows, wild shrubs, and small trees form an ecologically valuable, open, and extensive landscape. The promenade at the foot of the Sonnenberg that leads along the new development toward Kriens is continued under the bridge with a three-dimensional play landscape. Two airy rows of trees mediate between the bridge house and the new structures.