I was puzzled by why Whitefoot La and Southend La were these isolated bits of dual carriageway that seemed over-engineered for the location, and when I looked at a 1930s map and you could see that they seemed to be lined up with the similarly wide Jeavington way, via a non-existent bridge over the railway pointing towards the roundabout formerly known as the Land of Leather roundabout. So it looked to me like they intended to link these roads up eventually (I could be wrong). Although what would happen to all that traffic at the Bell Green end of Southend La, where Sansburys is, I don't know. Probably squirt it all up Sydenham High St.
As far as the ringways go, what a nightmare that would have been, with full fat 6 lane motorways all over the place. Although I have to admit that sometimes I sit in my car on the South Circular, occasionally inching forward, thinking that maybe they had a point. The
cbrd site is absolutely fascinating on that score.