Mr Red, thanks for posting that video about the diamond configuration. I like it. Ingenious! While watching it I just have to do a bit of mental gymnastics to translate it into driving on the left and not the right.

Our problem in Oz even with simple, single circle roundabouts is that a significant chunk of drivers don't bother sticking to the speed limit, don't give way to vehicles already on the roundabout, don't use their indicator to tell the rest of us where they are going & when they are leaving the roundabout, and often have an aggressive attitude to any other vehicles which have the hide to get in their way. Quite often they are driving 4WD utes or 4WD Balmain Shopping Trolleys (great big clean and shiny 4WD's which have never seen a dirt road, driven by people who just use them to buy groceries or ferry the kids to school).