Well, amazingly, the argument I heard was there was so much traffic coming Eastbound on the A47 wanting to go into East Norwich on the A1042 that when it was very busy traffic was queuing onto the A47 which was dangerous.
So the solution, obviously, is to close the link off and send the driver round something like seventeen roundabouts if they want to go to Thorpe St Andrew. Which will work really well.
On the upside they don't have to go through the Blackpool Illuminations (the traffic light junction). Children have been conceived and born trying to get past them.
I have a theory. Some dingbat in Norfolk County Council heard of Switch Island and thought it was some sort of Theme Park (Understandable, given the amount of time you can spend there), so they asked the staff to "build us something like Switch Island".