A crash involving a truck and a car is delaying traffic in both directions on State Highway 1 north of Puhoi.
The NZ Transport Agency said anyone driving north of Puhoi should expect delays in both directions and follow instructions from emergency services.
However, another accident between a truck and car which blocked northbound traffic on the Southern Motorway near Greenlane this afternoon has been cleared.
An agency spokeswoman said no issues with surface flooding or weather-related incidents had been reported anywhere on the Auckland motorway network so far.
"But in anticipation of bad weather, we advise motorists to slow down, take extra care, observe safe following distances and turn their headlights on," she said.