The highway bridge gently curves across the bay along Sweden's eastern coast, roughly 400 km north of Stockholm - in Sundsvall. It belongs to the expansion project of the European route E4 and closes a gap between Stockholm and the border to Finland. The project aims to enlarge the road network capacity, to reduce traffic jams and to redirect the traffic outside urban areas, thus bringing down the amount of emissions in Sundsvall and increasing road safety south of Sundsvall.
Moving the traffic outside Sundsvall’s city center has been studied for decades through a major road project and an urban development vision making it possible for the city to grow along the bay’s beaches and reach the water. A step towards realization was taken in 1995, when an open competition was announced.
The competition that was won by the project group K*R*A*M (a joint venture consisting of: KHR Architects with &Rundquist, Rambøll AS, Anders Nyvig, Möller&Grønborg) and their proposal, ”Dubbelkrum" but the commission has only begun in 2007, after more than 10 year of waiting due to the stall of the E4 project. In 2009, following an EU-wide prequalification, the client commissioned a group of contractors and engineers with the turnkey delivery of the entire bridge project.
The design relates to the city as well as the surrounding hilly landscape. Despite its tremendous dimensions and a length of 1420 m the bridge doesn't seem to dominate its surrounding. Instead, similar to a dialogue with the environment, it defines the bay as a new urban space. The movement across the bay describes a smooth curve both in plan and in profile, with the maximum height at the center. The bridge forms a sleek and unified line running from abutment to abutment, without detaching ramps or other disturbances.
The bridge consists of three different elements that visually contrast with each other whilst composing a constructive whole. Massive faceted concrete piers raise out of the water to about two thirds of the total height. On top of them extends a structure of steel pipes that bears with ease and transparence a wing-shaped steel deck.
The connecting ramps on both sides of the Sundsvall bay are designed to constitute a cohesive form of the steel structure and in the same level as the main lanes north-south and gradually widens towards the abutments. When the ramps lower, they form a new designed context that relates to the landscape and the roundabouts that connect to the local road network. The clear forms of abutments interact with a park-like environment with and powerful plantings of birch trees.
The abutments are made of powerful wall constructions that clearly mark the end of the steel deck. Their shape is inspired by the piers’ geometry, revealing a series of vertical grooves along the sides. E4’s stone cladded retaining walls run along the interchange ramps and are part of a coherent design for the traffic intersections.
The whole Sundsvall city center, originated from the 17th century, is named a National Interest of Cultural Heritage (Riksintresse för kulturmiljövården) by the Swedish state and there are several buildings that have been declared heritage buildings according to the Cultural Environment Act. The bridge design was rewarded by the jury for the competition as it, among other things, related to both the values of city center and the the large landscape and related to the free lines of sight of the city plan.
