Six trucks were torched on the Van Reenen Pass on Saturday night, leading to the closure of the N3.
A group of armed men reportedly forced truck drivers to stop and allegedly torched the trucks. The drivers were not injured.
By midday on Sunday, the southbound lanes were opened for traffic, following emergency road repairs. The reopening of lanes accommodated both directions of traffic using contraflow.
The northbound carriageway, towards Johannesburg, remained closed until repairs could be completed and the road deemed safe for passage, the N3 Toll Concession said in a statement.
Road users were advised to continue to expect congestion and delays in the area.
"Please slow down and continue to approach the area with caution,” said Thania Dhoogra, operations manager of N3 Toll Concession (N3TC).
“We thank our road incident management partners for the sterling support and continued efforts to restore traffic flow."
IOL