Seven and a half years ago, the newly elected mayor of Hamburg, Olaf Scholz, has immediately stopped all plans for a new tram system because he feared massive traffic congestions. I think he didn't want to lose his face in case the rich assholes of Eppendorf and Winterhude tried to stop the project because of their hatred of overhead wires and their opposition of anything that benefits anything other than their Porsches. Here you see the planned network of the Hamburg tram system. It mostly follows the most used bus corridors, and would've only needed a faster connection between Altona (where the first line in orange would've ended) and the city center (inside the purple circle). It would've largely lessened the cost of additional drivers and once a tram network is built, its operational cost is not something to worry about either, especially not in Hamburg.