The road is closed but an update from road authorities at 7am said it was expected to be reopened within an hour.
'There was moaning and screaming'
A resident, who asked not to be named, said he woke up to a loud crash outside his house.
"Man, it was really loud. It was just the loudest 'woomph'! The cops were right behind them. I jumped out and asked: 'Are you alright? Are you alright?'
"There was just moaning and screaming."
A photographer at the scene described the vehicle involved as "twisted metal" and said the passenger side appeared to have been cut to get at least one or two people out of the car.
A worker at the nearby GAS Kaurilands petrol station - on the corner of Atkinson Rd and Kaurilands Rd - said it appeared the crash happened a little further up the road, near Woodfern Crescent.
Standing outside just after 6am, he told the Herald: "There are cops up there, but the traffic is flowing both ways. There's one police car I can see - the lights are flashing."
Residents on a local community Facebook page reported hearing the collision, with one woman saying it "sounded pretty bad".
ATKINSON RD, TITIRANGI - ROAD CLOSED - 6:00AM Due to a serious crash overnight as section of Atkinson Rd, between Woodfern Cres & Daffodil St, is currently CLOSED. Please allow extra time for diversions in the area. ^TP pic.twitter.com/YAGHsvusuu