Freeways Exploratory drilling delays decision on the Zurich Oberland highway

Unexpectedly complex exploratory drilling is delaying the decision on the best option for a continuous Oberland highway by around a year. It will not be made until 2026. Astra is now also examining a continuous tunnel from Uster to Hinwil.

The 40 or so exploratory drillings from August 2023 to August this year provided information on the subsoil for the "deep tunnel" variant. This would lead directly from the Wetzikon junction to the Betzholz traffic circle in Hinwil, as announced by the Federal Roads Office (Astra) on Thursday. Various additional drillings were necessary because the geology turned out to be different than assumed.

However, it turned out that the rock runs deeper than originally assumed. A deeper route could therefore also be considered. However, this would make it necessary to dispense with a connection in Wetzikon.

New variant with long tunnel

For these reasons, the variant without a Wetzikon junction, the so-called "deep long tunnel", is now being examined. The tunnel would run directly from the Uster Ost junction to the Betzholz traffic circle in Hinwil, where the Oberland highway from Rapperswil and the Forchau highway meet.

In addition to the Wetzikon junction, this option would also eliminate the viaduct in Aathal. From November 2024 until spring 2025, a second stage of exploratory drilling will be carried out to clarify the geological conditions along the possible "tunnel deep long".

No highway through moorland

A solution for a continuous highway in the Oberland has been sought since the 1970s. The highway currently ends in Uster from Zurich and at the Betzholz traffic circle in Hinwil from Rapperswil. The distance in between is just under 10 kilometers as the crow flies.

In 2012, the Federal Supreme Court prohibited a planned route through a protected moorland area near Wetzikon. Planning had to start all over again.

SDA