A driver is seriously injured after a car and milk truck carrying more than 100 crates collided near Middlemore Hospital in South Auckland this morning.
A police spokeswoman said the accident happened on Gray Ave, Mangere, just after 5.45am.
The milk truck carrying around 120 crates of milk overturned on the busy suburban road.
The road near the hospital and De La Salle College was closed and traffic diverted around the crash scene.
More than four hours later the road in Mangere east was reopened to all traffic in both directions.
Police earlier warned congestion was likely near the college as children returned to school for the first day of term.
Traffic heading south was diverted around the crash scene. Road blocks were put in at the corner of Rosella and Gray Ave, Landon and Gray Ave and Earlsworth Rd and Hain Ave.
Motorists were asked to avoid the area if possible until police cleared the scene and reopened the road.
A police spokesman said the driver of the car was trapped and seriously injured.
The truck driver was not hurt in the accident.
Fire crews, police and ambulance were at the scene of the collision.
Fire Service northern shift manager Jaron Phillips said a truck carrying up to 120 crates of milk was involved in the crash.
The injured driver was in a serious condition, he said.