A Masterton man is in a serious condition after the logging truck he was driving slid out of control on Ponatahi Rd yesterday afternoon.
The 63-year-old driver was conscious when paramedics took him to Wairarapa Hospital, and his condition was described as "serious".
A second vehicle was involved in the crash, but it left the scene soon after.
The incident happened at 1.15pm, about 15km from Martinborough, on a downhill stretch of road near the intersection of Kokotau, Ponatahi and Millars roads.
Both lanes of the road were blocked to traffic for several hours.
Masterton Police Sergeant Chris Megaw said it appeared the trailer had flipped and slid down the road for about 65 metres before overturning the truck.
He estimated the truck and trailer unit was carrying around 35-40 tonnes of gum logs, which were being taken to a firewood merchant in Martinborough.
Specialist police staff would look at a number of factors to determine the cause of the crash, he said.
"Loading issues, mechanical issues and driver issues, capped off by environmental issues like the road conditions are what we'll be looking at."
Mr Megaw said it was not unusual to see a truck overturned, but the driver was lucky to not have more serious injuries and it was fortunate no one else was hurt.
"It's a road used by lots of people, somebody could've driven into it but they didn't, somebody could've been underneath it but they weren't."
Wellington Free Ambulance, Carterton Fire Brigade and police attended, and a local farmer was the first on the scene.
Burling Transport owner Fred Burling and his son were also on the scene, but declined to talk to the Times-Age at the time.