Another tree used as a street tree here is white cedar (native) and it would have the same problem with rotting flowers, plus far more annoying fruit/berries that cause slips and try to start rogue trees all over the place.

Incidentally, what are considered ideal street trees? I know plane trees are out of favour (lots of leaf litter, annoying flower ball thingies). Crepe myrtles aren't tall enough for roadside plantings.