State Highway 1 north of Topuni has reopened between Kaiwaka-Mangawhai Road and Mangawhai Road after to a crash in the early hours of this morning.
The crash involved a car and a light truck and as a result, one person was trapped and another was transported to Auckland Hospital in a serious condition.
A Fire and Emergency NZ spokesperson says they were called to the scene around 3.45am.
Auckland Westpac Rescue Helicopter were called shortly after and transported a woman in her 20s to Auckland City Hospital.
A St John report says a helicopter was also dispatched to the accident.