A replacement E4 tram will run from Schottenring to Nussdorf on the same route as the D tram, at five minute intervals during the day and 15 minute intervals during the night.
According to the Wiener Linien transport authority new crossovers will be installed at the weekend as well as track and power cables. The work will start on Saturday morning at 00:30, and will be finished by Sunday evening. The U4 should be running as normal by Monday morning.
The U4 line is being modernised at a cost of €335 million and work will be carried out over the next few years. Sections of the line are expected to be closed for several months in 2016 and 2017.