well, about all i can recommend at this point is to try to identify by the objects in the picture, as well as the yellow cab info. yellow cab is probably a north american only type company, at least at the time period of the picture. the bus isnt a bus at all. it's a streetcar, electric. those were almost completely gone by the 50's. i do recall seeing some in detroit in the 50's, but that was the last time. if you can get more detail on the clothing, that might help.
off hand, about the only guess i'd be willing to make would be the united states (and even that may be wrong), but i'm not a specialist, and that's kind of what you need at this point.