A man suffered chest injuries when two giant rear wheels from a truck and trailer unit came off and smashed into his car.
The 57-year-old Te Puke man was injured in the accident on State Highway 2 in the Bay of Plenty yesterday about 1.30pm.
He was travelling in the opposite direction to the truck.
Tauranga man Dennis Dobson was driving behind the victim when a set of rear inside dual wheels sheared off the trailer and rolled along the road.
The wheels crossed the median strip and struck the car in front of him.
"As [the truck] went past, two wheels came straight towards us and we had nowhere to go and the wheels smashed straight into the front of his car. The wheels bounced over the top of the roof of his car and towards me so all I could think about was trying to get out of the way," he said.
"I saw the wheels coming towards us out of the corner of my eye. In a split second, I realised what was going on and I braked heavily to avoid hitting the guy in front," he said.
He and another driver stopped ahead of the smashed car and ran back to see if the driver was okay.
"He was pretty dazed. He seemed to be okay but I think he might have had a bit of whiplash. He wasn't bleeding or anything."
"The airbags had gone off and that had obviously saved him. He was conscious but he was pretty shocked and a bit shaken around. I don't think he fully understood what had just happened."
Western Bay of Plenty road policing manager Senior Sergeant Ian Campion said the truck driver was oblivious to the accident and continued driving towards Tauranga.
The truck was able to continue because there was another axle at the rear. He turned back after it was pointed out to him by another driver.
"The truckie was quite devastated and visibly upset, and in fact he didn't know anything about it until he was stopped up the road," Mr Campion said.
He said the driver of the vehicle hit by the rogue wheels was treated by St John Ambulance officers before being taken to Tauranga Hospital.
Mr Campion said the cause was still being investigated and it was too early to say whether any charges would be laid.
- Additional reporting Sandra Conchie