A new link west of Stockholm has been under investigation for several decades and a large number of different alternatives have been studied. To reduce the impact on sensitive natural and cultural environments, just over 18 km of the total of 21 km of the motorway link are in tunnels.

The construction work is planned to start in 2013 and it will take 8 to 10 years to finish. When the link opens for traffic it will be one of the longest road tunnels in the world. By 2035, the Swedish Transport Administration (Trafikverket) estimates that Förbifart Stockholm will be used by approximately 140,000 vehicles per day.