 Lines 16 and 18 are the longest lines in the network, connecting Cologne to Bonn via railway lines.The Kölner Verkehrsbetriebe (KVB) opened a -long extension from the former Ossendorf terminus into the Butzweilerhof/Gewerbegebiet Ossendorf area in December 2010.Three new stations (Alter Flughafen Butzweilerhof, IKEA am Butzweilerhof and the new terminus, Sparkasse Am Butzweilerhof) were added to the existing Line 5.