It's the littering that gets to me. And the poorer settlements seem plagued by it. It's as if there is no drive to manage waste at all. I don't know how these people can live between so much rubbish scattered everywhere. I'd find it depressing.
The people grow up under such conditions. That is partly why South Africa is a nation of litterbugs and we have "troops of monkeys" littering the beaches of Durban: if you grow up in the midst of litter, it no longer strikes you as abnormal or unacceptable.
Here in and around Centurion, roads are quite well maintained. I now and then drive out to Bronkhorstspruit, and to avoid the toll road I use the old road; it too is in great condition and well maintained.
Looks like it's a bit of a mixed bag, and differs from area to area.