Motorists in the Canterbury area are being urged to take extreme care on frosty roads this morning.
Senior Sergeant Vaughn Lapslie said ice began to form on roads across the district last night, and remained “treacherous” this morning.
He said motorists should keep in mind that black ice was often very difficult to see.
Mr Lapslie said road contractors had been utilised overnight, and would be out this morning.
He said police were asking motorists to take care, and remember to allow for extra travel time and to drive to the conditions.