Cutting down those bushes would definitely have improved safety at the round about, Anyone who ever used the roundabout could have seen that.
It's almost as if the planners/consultants just looked at a map and saw "roundabout" without even looking at the actual site, so the obvious choice was to replace it with traffic lights.
What's really annoying is the fact that the roundabout was huge, it could have easily been rescaled to allow for 3 lanes around it with part time signaling for rush hour traffic.
My current theory is that one of the council planners keeps failing their driving test because they can't do roundabouts. So the obvious choice is to clear away all the roundabouts near the driving test centre.