I can see afew accidents happening there. Wiggi77- you'll be like many motorists, on your approach to the r/about not realising the fence is there obstructing the view.... and you pull out!!! Surely, giving the driver a better view of the traffic on the r/about is the sensible option especially given the national speed limits around there. A roundabout is a 'give-way' to allow traffic to flow not a 'stop'. The fences will cause tailbacks up the slip road as stationary cars are trying to join a fast flowing 40mph r/about.
There must have been some spare cash after fixing the m53 flyover or B&Q might have a Sale