Officers were called to the Crown Range road between Queenstown and Wanaka after several drivers spun in slippery conditions, and motorists were instructed to fit chains before heading up the alpine road from 9.15am.
Sergeant Tracy Haggart, of Queenstown, said police attended two incidents involving three vehicles at the top of the zigzags about 9am.
In the first, a vehicle slid on to the shoulder of the road, and a following vehicle slid in the same patch of ice, rear-ending the leading car.
Both vehicles had minor damage, but there were no injuries.
A short time later, an Alpine ConneXions van carrying six passengers slid on the first bend from the top of the zigzags, causing the luggage trailer it was towing to jackknife.
There were no injuries, and police helped to get the undamaged van and trailer back on the road.
A 29-year-old Queenstown woman was uninjured when her car rolled after sliding on ice in Goldfield Heights about 8am and, an hour later, a 58-year-old Queenstown man also avoided injury when his vehicle slid on black ice in Middleton Rd and hit a lamppost.
At 3.15pm, two drivers escaped injury when a vehicle pulled out of Sawmill Rd and ''T-boned'' another vehicle driving along Gorge Rd.
Sgt Haggart said although grit trucks were ''out in force'' in the morning, the incidents were the result of challenging road conditions and drivers failing to adapt.
''When there are extreme weather conditions, drivers need to take extreme caution and care.''
Queenstown's mountains and hills were coated in snow after an Antarctic southerly airflow hit the district on Sunday night.
Schools remained open, although the Queenstown Lakes District Council advised drivers black ice was widespread across the Wakatipu from Glenorchy to Gibbston.
Coronet Peak ski area manager Ross Copland said fresh snow was very welcome, with about 10cm falling at the peak and 5cm-7cm at the base building by 10am yesterday.
It was still snowing on the mountain yesterday afternoon, with close to 2000 people enjoying the conditions.
MetService meteorologist John Law said the southerly had brought with it very cold temperatures, showers and snow showers, and would remain ''firmly in place'' for the rest of the week.
Snow showers were forecast to low levels across Otago and parts of Southland overnight, with snow making travel on inland roads difficult.
