State Highway 1 north of Dunedin has been closed by heavy snowfalls, leaving about 150 cars stranded.[image:2560:half:right]
The New Zealand Transport Agency (NZTA) is assuring the stranded motorists that it is doing everything it can to clear the snow from the road so that they can continue their journey through to the city.
The agency says its contractors are working as fast as they can to clear the snow, which has left cars waiting at Kilmog Hill about 20 kms north of Dunedin.
NZTA spokesperson Murray Clarke says a hall in the nearby township of Waitati is providing food and shelter for the stranded travellers.
He says efforts are being made to find them a bed for the night but says otherwise people might have to turn around and travel back to Palmerston, about 30 kms to the north.
Earlier, police warned motorists in the south to take extreme care after more than 30 road crashes, many on Dunedin's southern and northern motorways.
Police are asking drivers to avoid all non-essential travel and, if they have to drive, not to make "silly decisions".
The bad weather has also been affecting South Island flights.
Air New Zealand says it had to cancel 22 return services from Queenstown, Dunedin and Invercargill on Sunday while Jetstar cancelled four flights in and out of Queenstown.
No major incidents have been reported on North Island roads but the MetService says the bad weather is moving rapidly up the country.
Forecaster Paul Mallinson says the storm will pass over the South Island overnight and move on to the North Island on Monday.
He says heavy snow is forecast for higher ground from Whanganui to Taupo and for Gisborne and Hawkes Bay.
He says it's possible higher areas of Northand and the Auckland region could also see some snow.