A motorist is critically injured after a serious crash on the Southern Motorway, forcing the closure of multiple lanes.
Emergency services were called to the crash in the northbound lane after a single car rolled near Redoubt Rd.
A number of northbound lanes have been closed following the 3pm crash.
A St John spokeswoman said one person suffering critical injuries has been transported to Middlemore Hospital.
One ambulance and one manager responded to the crash, she said.
State Highway 1 is closed from the SH20 Link (Airport link) to Te Irirangi Drive on-ramp as the crash is investigated, Waka Kotahi/NZTA says.
The Redoubt Rd on-ramp is also closed, as is the SH20 Link to SH1 northbound.
"Please delay your journey or use an alternative route," it advised motorists.
Traffic is quickly building in the area as emergency services attend to the crash.
Both lanes northbound were earlier blocked adjacent to the Ti Irirangi Drive on-ramp.
A police spokeswoman said the Serious Crash Unit was at the scene.
"Two lanes of the motorway are currently blocked, and motorists are advised to expect delays and avoid the area if they can," she said.
Fire and emergency services are on site, a spokesman confirmed.