A woman has been airlifted to North Shore Hospital in a serious condition after two cars collided on State Highway 1 in the Dome Valley north of Warkworth about 1.40pm today.
A vehicle turning into the car park at the bottom of Kraak Rd collided with a southbound vehicle, a Warkworth firefighter said.
Five people were in the southbound vehicle - a couple, their two boys and the boys' grandmother, a witness said.
The mother and grandmother were taken by ambulance to Warkworth Primary School where one was picked up by the Westpac rescue helicopter.
Police suggest motorists take the State Highway 16 alternative as only one lane is operating on SH1 in the Dome Valley.