I figured it was one of those proposals to get the rest of the document some attention in the press but which haven't got a hope of actually materialising.

I did read some of the documentation and apparently they will be doing feasibility studies in 2014 as to how this might happen.

Even if they did build something, I'm assuming it wouldn't necessarily follow the line of the current South Circ exactly - but just tend in the general direction. What I also don't understand with the proposal is that presumably it would have to surface regularly or have lots of slip roads and where on earth would they get the space to do those?