A crane is being brought in to move a truck after it rolled on its side earlier this morning near Wellington.
Central police communications Inspector John Spence said the accident happened 2km south of Masterton, when a truck rolled over on to its side, around 4am.
The driver of the truck was not injured in the crash.
He said a crane was now being brought in to move the truck, which was partially blocking one lane of traffic.
However, at this stage traffic was still flowing freely, he said.