The speed limits in South Africa differ depending on the area where you are, the type of road and what the authorities decide is safe. In built-up and urban or suburban areas, the speed limit is generally 60 km/h. On certain roads in the urban areas the limit might be as high as 80 km/h. Important is that near schools and churches speeds might be reduced to 40 or 60 km/h.
On highways and the open road’s the limit is 120 km/h, on secondary roads in rural areas it’s 100 km/h and sometimes even 120 km/h. The best is to look out for the road signs indicating the speed limit.