Northbound lanes on Auckland's Northwestern Motorway have been closed near Massey after a serious two-vehicle crash on Saturday night.
Emergency services were called after the vehicles collided on State Highway 16 in the motorway's northbound lanes, north of Lincoln Rd, around 7:30pm.
Police say a car appears to have rolled, and one person is believed to have serious injuries.
The road is closed and diversions are in place. Motorists are advised to avoid the area if possible.