Van Reenen’s Pass was closed to all traffic on Tuesday morning after two trucks collided.
Anita Heyl, spokeswoman for N3 Toll Concession, said that traffic had been stopped at the Tugela Toll Plaza in KwaZulu-Natal and that traffic was backed up near Harrismith in the Free State.
There were no reports of injuries or fatalities from the accident scene.
Heyl urged motorists to either delay their journey or take an alternatives route. The N3 was expected to be opened later in the day.