What’s the source for this?
I ask because this does (based on the imagery) very much seem to be a bike path that allows bikes traveling on miller road to navigate the roundabout through the pedestrian crossings by entering the sidewalk network were this way meets the road. This is a common pattern you will see in other parts of Miami dade, were at roundabouts you will see bike paths like this going to the street and thus allowing bicyclists rinding on that road to transfer to the normal sidewalks so that they can cross the roundabout through the same crossing individuals walking will use since it is safer that way.
Also as previously mentioned unless there’s a sign saying that bikes aren’t allowed on this way bikes are allowed and there isn’t any signs showing that in this area (based on the bing imagery available in iD) so bike=no shouldn’t be on this way. Also if this truly isn’t a bike path then it should be a sidewalk. 