I'm not sure that double-decking a tram is a good idea. Double-decking is alright for regional trains with infrequent stops, but trams have frequent stops and are more constrained by exits and enters on platforms. This design sacrifices a lot of floor space on the first floor in order to gain space on the second floor, which will then have far longer times to exit the tram, reducing the overall efficiency of the system. I'd rather see the money spent on either longer trams or just more frequent trams on a given line.