A Fire and Emergency New Zealand spokesman said two crews attended the accident and extricated one person from a vehicle.
The other car was engulfed in flames upon arrival but was soon extinguished by FENZ crew.
Emergency services are putting diversions in place on SH11 and ask motorists to be patient if they encounter delays.
UPDATE 8:30PM SH1 remains CLOSED between Hautapu Road and Nisbet Street. Please use the detour via SH11 and SH10. For further updates overnight, please check our Travel Map here: https://t.co/mNnq8OLDlc. ^EW https://t.co/CqBPx6Q0M0
— Waka Kotahi NZTA Auckland & Northland (@WakaKotahiAkNth) October 21, 2018