 The only completely new section is the connection over the Südbrücke (South Bridge), which is used by the 66 and 68 on the southbound journey from Bonn Hauptbahnhof to Ramersdorf and Bad Honnef.The "Stammstrecke" (trunk route) is the segment between the Bonn Hauptbahnhof station and the Deutsche Telekom stop at United Nations place, which is served by all Stadtbahn lines, but not by the three tram lines.The majority of the route runs through a tunnel constructed in 1975, replacing the BGM-operated tram tracks which ran above-ground along the Adenauerallee and down to Bad Godesberg.