>Roundabouts generally make streets safer for pedestrians as they slow the flow of traffic.

I wonder--if it's a busy roundabout. There's a lot going on and drivers are looking at traffic in the roundabout and in the upcoming entrance to the roundabout and mentally calculating if it's safe to merge in. At one particularly busy pair of local roundabouts (aka "the twin doughnuts of death") there's actually been a pedestrian/cyclist stop light installed because otherwise you'd be taking your life in your hands to get across the road.