But it’s not driving 75km on an 80km zone. It’s being stuck behind a 40 meter/ 120ft long truck going 80-90km/h in a 120km/h road. Obviously only perform an overtake when it is safe to do so, on a straight section of road with good visibility, no blind turns, crests, fog or mist. Rarther spend time behind the truck or slow vehicle, it’s much better than risking your life for an overtake. But it’s still preferable to spend as little time in the oncoming lane as possible, especially when overtaking such long truck/trailers with 30+ wheels. South Africa has a 10km/h speed limit tolerance both for this and other reasons (speedometer inaccuracies, etc).