Ice on the Northern Motorway out of Dunedin has prompted a warning from police for motorists this morning.
A ''quite treacherous'' patch of ice at the top of Pigeon Flat was extremely difficult to see, police said.
The area is approx 200m either side of Pigeon Flat where Leith Valley Road intersects with State Highway 1.
Contractors were applying grit, but motorists were urged to take care.
The New Zealand Transport Agency says most Otago roads are open but users are told to expect winter driving conditions.
