BVG had instituted a new line structure, where the BVG has 22 lines since 2004. MetroTram also uses the symbol . On 12 December 2004, BVG had introduced the transport concept, BVG 2005+. The main content was the introduction of metro lines on busy routes where there are no S-Bahn or U-Bahn. In the tram network, therefore, nine tram lines under MetroTram were introduced, and the other lines have permanently rearranged. The numbering scheme is that it was similar to the 1993 scheme, but has undergone major adjustments.