weekdays, every 10 minutes on weekends and since 2006 every 15-minute early mornings on Saturday and Sunday. On the other nights the "N3" bus service operates. Former U3 Until 1993 U3 referred to the section of line between Wittenbergplatz and Uhlandstraße, it was formerly numbered BII (until 1957), BIV (from 1957 to 1966) and Line 3 (from 1966 to 1984), before being renamed U3. In 1993, this section was renumbered to U15 and became a branch of the U1. With the change of train numbers in December 2004, there were some confusion as the planned final phase of the U3 line from Theodor-Heuss-Platz via Westkreuz, Adenauerplatz, Kurfürstendamm, Wittenbergplatz, Lutzowplatz, Potsdamer Platz, and Leipziger Straße to Alexanderplatz, and from there on to Weißensee and Karow-Ost, would overlap with the present course of the U3, as the provisional name would be with driverless Alstom Metropolis trains to be purchased for the U3. However, these plans were scrapped. References External links Berlin U-Bahn lines Railway lines opened in 1913 1913 establishments in Germany