Police are still at the scene on Blue Mountains Road in Upper Hutt where a truck is blocking the road and a trailer is hanging off the side of the road.
Police are looking at getting equipment in to cut the trailer from the truck in order to move it.
Blue Mountains Road will remain closed for some time, and locals are being advised to use alternate routes.
19 cows that had escaped the trailer are being rounded up by a local farmer. A vet has assessed the animals and none are injured. Stock control is on scene.
ENDS
Issued by Senior Sergeant Quentin Ward, Hutt Valley Police.