Final sign before ramp: http://goo.gl/maps/Q06cO
First sign on the ramp after leaving the highway: http://goo.gl/maps/85JLE
View of the actual intersection, for reference: http://goo.gl/maps/YvItp
Just a regular four-way intersection with a robot, not even a slip lane.
Following the UK guidelines, this ramp would be named: "N14 (S) 295 Exit to R512". That seems simultaneously too verbose, and too different to the actual signage. In particular, mentioning the name of the highway you are already on is either redundant (if you already know what highway you're on, you don't need Waze to tell you!) or confusing (if you don't know what highway you're on, the exit ramp sign is unlikely to tell you).
Following the US guidelines, this ramp would be named: "Exit 295: R512 Randburg / Lanseria / Brits".
If we split the ramp near the end, the terminal segments could be named like "Exit 295: R512 Randburg" and "Exit 295: R512 Lanseria / Brits". This would unfortunately make the road geometry more complicated, but might be worth it to shorten the naming. Judging from the information I've seen elsewhere on the wiki, it looks like the TTS *should* insert a pause for a slash with spaces around it (like "Lanseria / Brits") although it does not insert a pause if there are no spaces around it (like "Lanseria/Brits"). I still need to verify this locally.