One person is suffering serious injuries after a car crash on the Upper Harbour Motorway in Hobsonville.
Two cars crashed on the motorway just before the Trig Rd offramp on State Highway 18, police said.
St John Ambulance said four people were taken to Auckland City Hospital, one with serious injuries and three with moderate injuries.
The motorway westbound is closed and traffic is being diverted, police said.
Police were advised of the crash about 6.50pm this evening. Fire and Emergency were also at the scene, they said.
Motorists are advised to expect delays or avoid the area if possible.