The U4 modernisation project

The largest modernisation project in the history of Vienna’s underground network

The modernisation of the U4 underground line ("NEU4") is the largest round of modernisation work to be performed in the history of the Vienna underground system. 

The City of Vienna and Wiener Linien are investing EUR 335 million in the NEU4 project to improve the U4 underground line. This modernisation work includes the replacement of signal boxes and the renovation of tracks, track foundations, stations and tunnel ceilings. Additional track connections will also make it possible to change tracks in the event of disruptions, helping to improve the reliability of the U4’s operations.

Work began in spring 2014 and will continue until 2024; in the final phase after 2019, however, this work will have a negligible impact on U4 operations.

Schedule

2015

  • Modernisation of the Hütteldorf and Meidling Hauptstraße signal boxes
  • Renovation of the Hütteldorf station
  • Start of work to renovate the Stadtpark station
  • Start of work to renovate the supporting wall between Ober St. Veit and Karlsplatz

2016

  • May to September: Closure between Hütteldorf and Hietzing due to complete modernisation of tracks and track foundations
  • July and August: Closure between Hütteldorf and Schönbrunn due to modernisation of tracks and track foundations
  • Completion of work to modernise the Hütteldorf and Meidling Hauptstraße signal boxes
  • Installation of new track connections between Unter St. Veit and Ober St. Veit, Hietzing and Braunschweiggasse, as well as at the Schönbrunn station
  • Essential improvement work is carried out at the Ober St. Veit, Unter St. Veit, Braunschweiggasse, Hietzing and Schönbrunn stations
  • Renovation of the tunnel structure between Schwedenplatz and Schottenring

2017 and 2018

  • Spring 2017: Installation of new track connections on the northern section of the U4, with limited weekend services
  • Modernisation of the interlockings at Karlsplatz, Schottenring and Wasserleitungswiese
  • General renovation of the Roßauer Lände and Friedensbrücke stations
  • Summer 2018: Modernisation of turnouts and track systems around Heiligenstadt

2019

  • July and August: Closure between Längenfeldgasse and Karlsplatz due to complete modernisation of tracks and track foundations
  • Installation of new track connections between Margareten Gürtel and Pilgramgasse, as well as Kettenbrückengasse and Karlsplatz

2020 to 2024

The final phases of the project to modernise the U4 will be completed by 2024. The work carried out during this phase will have little impact on normal U4 operations. Other station buildings will be modernised, escalators replaced, tunnel linings renovated and track connections installed.