If it wasn't bad enough for the traffic to be crawling on the southern motorway near Papakura last night - a sheep had to add to the chaos.

Motorists were shocked to see a sheep stuck on top of a truck on Sunday afternoon.

The HTL truck had pulled over to the side of the road and had its hazard lights on as the truck driver can be seen walking around to the back of the truck and sizing up the situation.

The sheep was standing on top of the truck on the north-bound lane of the Southern Motorway between Drury and Takanini.

Sarah Doncaster was travelling north on the Southern when she noticed another commuter who became fed up with the waiting.

Posting a photo to Facebook, Doncaster said: "Traffic is bit slow on the southern this evening. Even the cargo got annoyed with it."