The Sihlhochstrasse, a section of Zurich's urban motorway, already caused a great deal of controversy during its construction.[1] 

After the first renovation work in 2002, a remaining life span until 2050 was defined. Today, it has reached two thirds of its service life. A core refurbishment is imminent, but a new building is more likely to be economically realistic. The next refurbish-ment is expected in 2030 - further utilization scenarios for the Sihlhochstrasse are to be discussed in the same year.[2]

The structure consists of a 1,494m long main bridge with three dilatation sections and adjoining ramp bridges totaling 1,016m in length. The normal span of the main bridge is 42.40m and consists of two box girders connected by a carriageway slab. It rests on massive pairs of columns, which distribute the loads to point foundations drilled 5-30m deep in the riverbed. [3]

The Sihlhochstrasse currently separates Zurich's 2nd and 3rd districts as a clear aisle. If one imagines a demolition or transformation of the structure, a new urban space opens up that could create new connections between the neighborhoods through targeted interventions. Just as relevant as considerations of a potential conversion for residential or cultural purposes is the future handling of the site as part of an already exceptional open space, characterized by the course of the Sihl river.

[1] «Aktenzeichen Y ungelöst»: Das Zürcher Expressstrassen-Ypsilon ist Geschichte. Wird die Sihlhochstrasse zum Baudenkmal?», NZZ, 15.08.2024
[2] Aktenzeichen Ypsilon ungelöst, Martin Jakl, Masterarbeit an der TU Berlin, 2018
[3] Spannglieder, Schrägseile und Anker. Beschreibung der Systeme und Erkenntnisse aus Korrosionsschäden,Forschungsauftrag AGB2000/470 auf Antrag der Arbeitsgruppe Brückenforschung (AGB), August 2005

Thank you, Martin Jakl