The NZ Transport Agency says State Highway 1 has been closed to all southbound traffic after Ramarama, due to an incident.
The Ramarama off-ramp is open, but is heavily congested.
Motorists are advised to leave the motorway at Drury and use Great South Road, and access the motorway again at Mill Road.
Traffic through the area is heavy and motorists are being advised to expect delays, avoid the area if possible and allow extra time for their journey.
