I can confidently say that something else have been discussed by senior politicians as well. This is still in talks only, nothing on paper as yet, but they are looking at, over and above the eToll system for charging fees when people enter different neighbourhoods, no matter what road you take - the same principal used in London.
If this is about to go through, they want to test it in JHB CBD, Sandton and Midrand. Talking about a R5 to R10 fee for entering the CBD per day. You may get a monthly or annual bill.