Seven people have been injured in a five-vehicle crash on State Highway 8 between Lake Pukaki and Tekapo.
Hato Hone St John ambulance staff treated one person in a moderate condition and six others with minor injuries after the crash near Tekapo Powerhouse Rd just after 10am on Wednesday.
It sent two ambulances but none of the injured people were transported to hospital.
NZ Transport Agency Waka Kotahi put a temporary 50km/h speed limit on the road earlier this week because of fog and black ice.
The road reopened on Wednesday afternoon, with NZTA urging motorists to watch their speed and drive with extreme care.
The area is often hampered by icy conditions during winter months.
Nearby Mt Cook village was sitting at a frigid -7.2 deg C at about 10am, and there are reports of black ice and fog in the area.
Meanwhile, steep streets in Dunedin turned into icy slip and slides, sending walkers skittering down footpaths and clinging to poles to stop themselves skidding.
Southern police received multiple reports of icy roads across the region, particularly near Heriot Row and London St in Dunedin.
Motorists were urged to take extra care and allow for extra travel time.
-RNZ and ODT Online
