Around 1.4 million people currently use the metro in Vienna every day. At the moment the Vienna metro network comprises five lines, 101 stations and an operating length of 74 kilometers. The intention is to expand the metro network to 90 kilometers and 116 stations by 2019.
In the course of the third stage of expansion Herrenknecht Mixshield technology was employed for two sections. For the extension of Line U1 (North) the S-222 excavated in 2003 within only nine months a tunnel of 824 meters through sand and gravel. The S-227 started tunnelling in January 2005 for the extension of the Line U2 and crossed the finish line after eight months and 1,728 meters in August 2005.