Road Traffic Management Centre (RTMC) spokesperson Ashref Ismail said: "We can confirm that the N1 road between Beaufort West, Victoria West and Richmond in the southern part of the Western Cape is closed for motorists as a result of the extreme weather conditions."
Ismail urged motorists to postpone trips to these areas and to avoid using routes in areas experiencing snowfall.
The South African Weather Service had forecast heavy rain and snowfall in Cape Town, KwaZulu-Natal, Eastern Cape and the Free State, while Gauteng and other parts of the country were experiencing extreme cold.
The hardest hit areas were the Eastern Cape, parts of the Western Cape, the southern parts of the Northern Cape as well as the southern Free State.
Snowfall on the Tsitsikamma and Outeniqua Mountains in the Western Cape started on Friday morning.
In the Eastern Cape, four people were killed when two vehicles collided at the Panhoek Pass on Friday. The accident was likely caused by poor visibility and the roads being slippery.
Ismail said they were expecting high traffic volumes along the N1 from Polokwane to Gauteng, the N3 from Durban to Gauteng as well as the N4 from Mpumalanga to Gauteng later this afternoon as schools reopen next week.
"Our message is clear to motorists, don't speed and avoid unnecessary overtaking," he said.
