All southbound lanes are now open however delays remain back to the city and rubberneckers are also causing delays for northbound traffic.
Motorists are advised to use alternative routes.
North Shore traffic should consider using SH18, SH16 onto SH20 to head to South Auckland and the airport.
Traffic heading south out of the city consider taking the Ellerslie Panmure off-ramp onto the Ellerslie Panmure Highway and using Great South Road and the Mt Wellington Highway.
The motorway over height detection system was operating at the time.