The driver and sole occupant of the car suffered serious injuries after he was thrown from a window of the car onto the road. His condition was initially thought to be critical but he is now stable.
Early indications were that the man had been drinking before the crash, police said.
The Waitemata Serious Crash Unit is investigating the crash that happened just before 6.30pm between Onewa Rd and Esmonde Rd in a southbound lane.
Two lanes were blocked leaving traffic down to one lane for about an hour.
Earlier in the evening Palmerston North based Rescue Helicopter was sent to Apiti where a 28 -year-old Feilding man suffered multiple serious injuries in a car accident.
The on-board St John Ambulance Intensive Care Para-Medic stabilised the man before he was airlifted to Palmerston North Hospital in a critical condition.
Crew used night Vision Goggles during the job.