This problem is not confined to the heavy rail network. In December, Munich Transport (MVG) was finally granted approval for the commercial operation of its fleet of Stadler Variobahn LRVs, after a three-year delay. In Germany new trams are approved by a technical authority (TAB) working for the government of the appropriate state.

In Bavaria there are two such TABs, and the extreme contrast in their performance has prompted Mr Herbert König, MVG CEO and chairman of the light rail division of the Association of German Transport Operators (VDV), to call publicly for LRV approvals to be standardised at a national level.
The MVG Variobahns (pictured) were ordered as part of a joint tender between the Bavarian cities of Munich and Nuremberg, and while both cities opted for the same vehicles, different TABs were involved. In Nuremberg, approval was granted without undue delay, while in Munich the process dragged on for three years. MVG estimates that the additional cost in staff time and consultants fees exceeds €1m.

The vehicles initially entered service in March 2009, but were withdrawn in July 2010 on the instruction of the Upper Bavaria TAB, which cited among other reasons a lack of documentation setting out street dimensions and bridge weight analysis for lines the LRVs might operate over, even though the Variobahns weigh less than the vehicles they have replaced. Details as minor as the position of passenger stop buttons were subject to detailed "change impact analysis" by the TAB.

Stadler told the German media it was perplexed by the complexity of the approval process in Munich, pointing out that certification of Variobahn vehicles in other German cities such as Bochum, Potsdam, and Nuremberg has been achieved with barely a hitch. The government of Upper Bavaria claims the additional testing was justified because the MVG vehicles are different from those of other operators.

This saga sets an unfortunate precedent for German LRV approvals, and one both suppliers and operators will be keen to avoid repeating elsewhere. It also suggests a debate is urgently needed on standardised certification, and who ultimately shoulders the risk for approvals.