A truck driver has suffered moderate injuries after colliding with a tractor in North Otago.
The crash happened about 4.45pm on Wednesday, 3km north of Hampden on State Highway 1.
Fire crews had to free the truck driver from the wreckage. The tractor driver was not hurt.
The road has partially re-opened on Wednesday night and is down to one lane while emergency services deal with the crash.
There is a significant build-up of traffic and motorists should expect delays.