Less through traffic! That's what the people of Zurich aimed at. To meet these demands a western bypass is to be built which would reduce traffic through the city coming into and out of Central Switzerland. The longest underground stretch will be the Islisberg tunnel with two tubes and a length of five kilometers.
Tunnelling work with the Single Shield TBM by Herrenknecht on the western tunnel was completed in April 2005, after just 54 weeks of single shift work. The TBM was then repositioned and converted before starting work on the next tunnel. After one year's tunnelling, breakthrough of the eastern Islisberg tunnel was achieved on July 12, 2006. On November 13, 2009 the tunnel was opened to traffic and from then on relieves the people of Zurich off the trough traffic.
Western Bypass Zurich (German)