A police spokesperson said initial indications suggested one person had received critical injuries.
The Serious Crash Unit had been advised.
“Diversions are currently in place and police advise motorists to avoid the area or delay travel where possible,” they said.
A Fire and Emergency spokesperson said two fire trucks responded to the crash.
“There were no persons trapped. The crew have left now.”
Waka Kotahi NZ Transport Agency issued an alert to travellers advising them that State Highway 16 had been closed between Kiwitahi Rd and Muriwai Rd roundabout north of Waimauku following the crash.
“Delay your journey or allow extra time for a detour.”
Bus services to Helensville and Parakai are also impacted following the crash.
Auckland Transport said 125 and 125X bus services had no access to Helensville and Parakai due to the crash.
Hence, “125/125X bus services to Westgate will commence their services at Stop 4524 - Waimauku Park and Ride”.
A Hato Hone St John spokesperson said they were notified about a car accident at 6.18am on McPike Rd and SH16, Waimauku.
“Three units responded, including one ambulance, one manager, and one rapid response unit.
“Our ambulance crews treated and transported one patient in a critical condition to Auckland City Hospital.”