Cutting edge in planning and design, the new Motorway 73 in Sweden was planned to save lives – and please the eye. A new road always involves an intervention in natural and cultural environment, and there was much to preserve and take care of when the new Motorway 73 was planned. Covering a 57-kilometre stretch from Stockholm to the coastal town of Nynäshamn in the Södertörn region of Sweden, the new road travels across large areas of untouched nature ideal for hiking, biking, swimming, fishing and picking berries and mushrooms. The landscape is dominated by rugged mountain- and rock formations and old meadows, and its rich diversity of flora and fauna holds several endangered and rare species, including eagles, osprey, harriers, elk, wild boar, lynx and deer. These conditions posed unique challenges to architects and road planners when the old, notoriously accident-prone road 73 needed to be replaced with a new and improved one.
The Swedish National Road Administration commissioned Erik Andersson Architects to be in charge of bridge design for the project. Esthetically, the 20 different concrete bridges were based on a theoretical system that allows the number of surfaces to be greatly reduced, while the forms change continuously depending on each bridge’s span and width. The sections flow from completely triangulated structures through curved to straight shapes in an ever-changing, yet harmonious progression, turning the bridges into members of the same conceptual family, perfectly adapted to each specific location. Safety was a key concern for the new road, which is also reflected in the bridge design with emphasis on clear views through streamlined shapes. In addition to motorists and pedestrians, even horses, elks and frogs travel safely over and on the new road – moving along their own specially designed bridges. Keeping them away from the cars on the motorway. The project was realised in collaboration with engineers Bjerkings, engineers Konfem, and landscape architects at Landskapslaget and Ramböll.