I would say at least 10% of drivers are in the wrong lane every day. Unfortunately I cross that roundabout at least 4 times a day.The Echo reporter filmed the chaos when it first opened, think there were some accidents as well.
I have only used it once when It opened, coming from Dorchester direction on A31 and wanting to get into Ham Lane towards Longham, went into Lane it mentioned, only to find a bit further on you needed to move over into another lane again, it was the first and last time I used it in that direction.