"I remember thinking, 'this is it' and then as soon as I came to a stop my first thought was 'have I hit anyone?' Because I didn't know what had happened. I still can't believe how it happened, it's amazing."
Witness Dan Forrest was travelling uphill on the State Highway 2 stretch of road with two others, when they saw the trailer skidding out as it approached them.
"We were just waiting to see if we would have to swerve but luckily it stopped just in time before it got to us," he said.
It came to a halt only 10m away from their van, missing any traffic.
"If anybody had been there they just would have got slammed into there [the hillside bank]."
Waipukurau police Senior Sergeant Ross Gilbert said the road took five hours to clear, causing considerable time delays for commuting vehicles.
One witness said he saw "hundreds" of cars queuing to get past the wreckage. "I only waited about 20 minutes, but on the southern side of the road there was a huge line to get through," he said. "There would have been hundreds of cars."
Traffic was directed at the scene by Otane firefighters while police and a towing company winched the trailer and truck cab from the shallow ditch it had ended up in.
"The road took approximately five hours to clear because of the heavy nature of the vehicle and we had to get all the heavy lifting equipment," Mr Gilbert said. He said investigations were still under way to determine if charges were likely.
- APNZ