By 2012, the € 1.5 billion BanaVäg West project to expand the railway and European route 45 will reduce travel time by up to 20 minutes in the valley.

The project is one of Sweden's biggest infrastructural investments and spans over 75 km in a sensitive and geotechnical difficult environment.

One project, multiple disciplines

COWI was asked to create the master design of roads, railway foundations, bridges, retaining walls, noise barriers and commuter train stations for a nine kilometre stretch squeezed in between steep rock faces and the Göta River.

The geotechnical and environmental challenges called for COWI's expertise within a multitude of disciplines from rock, electrical and environmental engineering to mapping, cost estimation and risk analysis. It was held together by tight and focused project management to ensure a delivery on time and on target.

"The practical implementation of the project with little room for rerouting traffic is nightmare in terms of project management. But COWI was a very competent and professional partner. They planned the implementation of the various stages with us and made sure everything went according to schedule," says Sara Larsson, Trafikverket.

Green concern

Industrial pollution along the Göta River meant COWI had to remove 100.000 tons soil containing high contents of lead, mercury and other toxic substances.

The water from the soil was recovered and cleansed before it was led back into the river, while contaminated surface water from rail and road in the future will be processed in special dams to reduce environmental impact.

To reduce the risk of flooding and support the expansion to double-track, the ground level was raised and chalk was mixed into the ground.

"It was very satisfying to be able to improve the environment and infrastructure at the same time," says Christer Niland, COWI.