Bundeszentralamt für Steuern
Metro began pre-construction in July 2012, and a Notice to Proceed was issued by Metro in September 2013. An official ground-breaking ceremony for the project was held on January 21, 2014. Heavy construction began in June 2014 and initial revenue service was projected to begin by mid-2020. , the line is behind schedule but is 98% completed. Revenue service is now expected in November 2022.