The N3 at Van Reenen's Pass in KwaZulu-Natal, was reopened on Friday afternoon after two trucks collided, resulting in a 4km-long diesel spill on the road.
In a statement, N3 Toll Concession's (N3TC) commercial manager Con Roux said motorists should, however, continue to expect delays as the traffic backlog starts to clear.
Delays should be expected between Harrismith in the Free State and Ladysmith in KwaZulu-Natal.
11h30 #Crash update N3-6X 60.0 Caltex #VanReenen: The entire #N3TollRoute is now open in both directions, north and south. Please beware of slow moving traffic on the south bound with slight backlogs still being experienced. Travel safely!-- N3 Toll Concession (@N3Route) December 15, 2017
"N3TC wishes to express its gratitude toward emergency services and rescue teams who have pulled out all the stops to speed up the recovery and mop-up operations," Roux said.
"They did a sterling job in the shortest possible time."
One person died in the N3 crash, while two people were killed in a separate incident at the Caltex Petrol station in Van Reenen, KwaZulu-Natal Emergency Medical Services spokesperson Robert McKenzie told News24.
McKenzie said seven vehicles collided at the petrol station, injuring 11 people.
Meanwhile, Roux warned motorists to expect high traffic volumes along the N3 over the upcoming weekend as holidaymakers head toward KwaZulu-Natal.
"We thank our road users for their patience and understanding under trying circumstances. Please keep safe on the road," he said.