N4/N20 freeway, Zurich Western Bypass, electromechanical installations, Switzerland

N4/N20 freeway, Zurich Western Bypass, electromechanical installations

Zürich, Switzerland

Project facts

Client: Civil Engineering Department, Canton of Zurich

Project Period: 1997 - 2010

Services: Preliminary design, final design, tender documents, tender process, bid evaluation, recommendations for contract awards, technical construction supervision, completion

The Zurich Western Bypass connects the existing freeway junctions of Urdorf-South in the West and Zurich-Brunau in the East with a two-way, four-lane freeway. An access road to the freeway (direction Zug/Lucerne) is planned from the junction of Zurich West.

The entire road is approximately 30 km long and goes through five tunnels as well as the junction of Zurich West. The daily traffic volume is estimated to be up to 70,000 vehicles.

The project was divided into three sections that were opened in stages between 2006 and 2010 and included the following tunnels:

  • Birmensdorf bypass
  • Eggrain/Ristet tunnel
  • Hafnerberg tunnel
  • Aescher tunnel
  • Uetliberg tunnel
  • Islisberg tunnel

The scope of work provided by Pöyry comprised:

  • Energy supply
  • Lighting installations
  • Tunnel ventilation systems
  • Measuring and monitoring installations
  • Central control systems
  • Cable systems
  • Appurtenant structures
  • Communication equipment
  • Overall coordination