This fence is built across Waldron Avenue, splitting the block in two. A similar fence exists one block over on Beverly Avenue, and a simple chain blocks traffic on Victory Boulevard from turning onto East Cheshire Place. This map shows the layout of the barriers.
One neighbor who was out in his lawn told me the roadblocks have been here as long as he can remember. He said they were a response to heavy volumes of cut-through traffic. They seem like overkill though. Why do the two fences need to prevent pedestrians from passing though? It's hard to imagine the DOT approving pedestrian barriers in an attempt to keep cars from cutting though an area.
Also, as you can see in the map linked above, the roadblocks kind of just shift the problem from one street to another. They prevent traffic from cutting through on East Cheshire Place, but they allow it on Melrose Avenue. So all the drivers trying to avoid the major intersection of Victory Boulevard and Clove Road can still cut through the area, just on a different street. The barriers are effectively sacrificing one street for another.
So how does something like this that needlessly obstructs pedestrian traffic on public streets and favors one street over another get built? Perhaps the answer lies in something else the guy out in his lawn told me: that some "important people" used to live here.