Partnering with a local consultancy, we are designing one of Sweden’s largest civil engineering projects – the Stockholm Bypass.   

This new dual, three-lane highway forms part of the existing E4 highway, linking the northern and southern parts of the Swedish capital. Of the road’s 21 kilometres, 18 kilometres will be in subterranean tunnels – one of which will be among the world’s longest in the proximity of a city.   

When complete, the bypass will not only relieve congestion in the city centre but also reduce impact on the environment and surrounding residential areas.  

What is our role in the Stockholm Bypass?

Harnessing our expertise across structural engineering, project management, building information modelling (BIM) and geotechnology, we are guiding both the design and construction of the new road link. This includes the subterranean tunnels – some of which are up to 100 metres deep.  

Our work on the bypass comprises two major components. Firstly, building new bridges, underpasses, tunnels and retaining walls, and upgrading current structures at the major Akalla/Häggvik interchange.  

Secondly, minimising environmental impact when excavating and transporting the 19 million tons of rock to accommodate the tunnels. Due to the project’s magnitude and scale, collaboration has been critical.   

This has involved a coordinated effort of more than 500 designers from 19 disciplines across seven countries. Together with our partner, we’re helping the client navigate complex challenges unique to tunnelling underground, such as solving water leakage issues and problems with rock quality. 

Of the road’s 21 kilometres, 18 kilometres will be in subterranean tunnels – one of which will be among the world’s longest in the proximity of a city.   

Efficient data handling 

With the design of the rock tunnels alone requiring over 50,000 documents, we had to adopt an efficient method of collecting and sharing this data. To do this, we hosted workshops to help select a suitable common data environment (CDE) to use with BIM.  

Thanks to the software we chose, the design teams could collaborate, assess and test their work in a virtual environment. This enabled them to develop innovative methods, cut construction-related risks and ensure they implemented environmental measures.  

In addition, we are helping the client reduce costs during production. This means working closely with client specialists to find cost-effective solutions. 

Protecting ecosystems, connecting communities 

By diverting traffic underground, the Stockholm Bypass promises multiple benefits. Besides shielding fragile ecosystems such as Lake Malaren – Sweden’s third-largest freshwater lake – the tunnel will also minimise impact to surrounding residential areas and cultural sites.  

Expected to be open for traffic by 2030, the bypass will be used by an estimated 140,000 vehicles per day by 2035, according to the Swedish Transport Administration (Trafikverket).  

This will significantly relieve congestion in the city centre, improve accessibility to other parts of the country and help create a more connected and liveable capital.