A person was injured and being treated by ambulance staff at the scene.
Rubberneckers also contributed to delays.
A recent vehicle breakdown heading into the city on the motorway at Greenlane had left an heavy patch of traffic between Mt Wellington and Greenlane.
The vehicle had been moved off the road but the impact of the temporary lane blockage was proving a headache for motorists who were being warned to allow extra time for travel this morning.