Strong winds whipping the Western Cape blew a truck over in Klawer on Saturday morning, provincial traffic officials confirmed.
Traffic chief Kenny Africa said a truck overturned on the N7, leaving only half a lane open.
No one was injured in the incident.
In the video, the truck can be seen swerving along the road as the driver attempts to keep control of the large vehicle.
The strong winds eventually get the better of the vehicle after 20 seconds, with the truck collapsing on its right side onto the oncoming lane.
Africa warned that at the Huguenot tunnel, strong winds of between 98 km/h and 120kph have been recorded.
"Motorists towing caravans and truck drivers [are warned to] be aware of the dangerous situation we are currently experiencing," he said.
The South African Weather Services has advised the City of Cape Town's Disaster Risk Management Centre of gale force winds on Saturday and Sunday.
"South easterly winds of between 60 and 70 km/h, gusting up to 90km/h in places are expected over the Cape Metropole," disaster risk management spokesperson Mandy Thomas said.
"All City services are on standby for any eventualities."