 The largest part of the trams route, between the Gasthuishoeve stop and Astrid, and between Diamant and the Olympiade terminus, were already being used by tram routes 2,3 (and partially 5 and 15).The part between the Metropolis terminus and the Gasthuishoeve stop was not in use by a regular tram route before the opening of route 6, but was already built, and was used by trams when going to, or coming from the" Punt aan de Lijn" depot next to the Metropolis complex.The small part of the pre-metro network between Astrid and Diamant stations, part of a railway triangle, was also already present, but was until then only used by trams when not in service.