Due to the new outskirts of Vienna in the fledgling Republic of Austria, the traffic flows had also changed greatly, especially the traffic to the north and east collapsed almost completely. In addition, as a result of the war for the first time ever in history, the population of the capital fell, and the prospect that Vienna would grow to four million inhabitants, was now no longer realistic. Thus, from the point of view of the former operator, no profitable Stadtbahn traffic could be expected. Furthermore, the fumes of the steam operation had - as already feared at the opening - especially the reinforced concrete ceilings and metal girders in the tunnel structures heavily added, so that the infrastructure of the Stadtbahn was in poor condition after the war. The tunnel ceilings then had to be repaired using the so-called Torkret method, i.e. the use of injection cement.