All three southbound lanes are closed in the Ngauranga Gorge following a slip. Two northbound lane are also closed to allow contractors to access the area.
Maintenance crews are on site to clear the road and police have traffic management in place.
Vehicles should divert to State Highways 2 and 58, with city traffic using the Ngaio Gorge.
Motorists are advised there will be delays for some time and are advised to delay travel.