An 18-wheel truck has tipped on State Highway 1 in Auckland while a nearby multi-car pile-up has completely closed all northbound lanes, causing kilometres of gridlock in south Auckland.
The New Zealand Transport Agency is warning drivers to avoid the main highway between Takanini and Papakura following two significant crashes on Wednesday morning.
An 18-wheeler had tipped on its side on the Takanini on-ramp and another multi-car crash further up on the same stretch of motorway had compounded to create traffic woes, a Fire Service spokesman says.
The driver of the truck was not seriously injured, police say.
However, the truck was spilling oil onto the road, and the on-ramp was expected to be closed until 2pm.
The other pile-up that closed all northbound lanes has since been cleaned up and traffic was moving again by noon.
One person received minor injuries in that crash.
Queues were stretching back as far as Drury by 11am.