I live on the west side of Milwaukee and commute downtown. I only see a one or two other commuters on my way into work, but I think that is due to the fact that less people are going in opposite direction. I know there are other bikers heading downtown (I see their tracks), but I don't see them as we are all heading the same way and travelling about the same speed. On the way home I will take a path (Hank Aaron Trail) and see more people in nice weather, but I am not sure all are commuters.