A large crane is on site removing the vehicles but transport authorities are warning it will be some time before the motorway reopens.
One commuter posted on social media she had taken two hours and 45 minutes to get home from the city on what was normally a one-hour journey.
Detours are in place via State Highway 16 but traffic is still extremely heavy. Earlier this evening it was taking up to an hour for cars to travel the 20km between Constellation Drive and the Silverdale offramp, where the northbound diversion begins.
The NZ Transport Agency is asking people to delay any non-essential travel or allow plenty of time for their journeys.
A breakdown on the Harbour Bridge was also blocking one northbound lane earlier, creating further delays for northbound traffic.
Traffic on other Auckland motorways was also heavy due to rain and crashes this afternoon.
They include a crash blocking one lane of southbound traffic on the Southwestern motorway just before Massey Rd, and a crash near Bombay, blocking one southbound lane just before the SH2 turnoff.