This is one of the ~30 badge ides I’ve got written up 
with a lot of the ideas coming from Badges for milestones
There’s also a whole “leveling” system that’s in place and functioning, I just haven’t gotten around to displaying it yet. So, the International Badge currently has levels for each country past your second (if your country count is 7, then your badge level is 6).
The badge name I have in mind for this is “Street Sweeper” (though that name might go to the streak-based badge I have in mind since “Street Streaker” doesn’t sound nice at all) and its level system will either be a new level every e.g. 10 streets or levels at e.g. 5, 10, 20, 50, 100, 200, 500, + streets.
At the moment, I kind of like the idea of a runaway level number by leveling up every 10 streets. The current global leader would be level 3,629 … The CHAOS 