In the worst accident, six vineyard workers from overseas were injured and State Highway 8A near Luggate was closed for just over an hour after the driver of a van lost control in extremely icy conditions on the one-lane Luggate Red Bridge.
At Roaring Meg on State Highway 6, two more vans, each carrying two people, collided about 8am yesterday.
Constable Dave Felstead, of Queenstown, said all four people sustained minor injuries.
Although he deemed it too early to conclude weather a contributing factor, Constable Dave Felstead said "it's a timely reminder" to drive to the conditions.
A car driven by a 76-year-old woman collided with a herd of cows on the Patearoa to Ranfurly road yesterday.
The driver sustained minor injuries and three cows died, prompting Senior Constable Steve Burke, of Ranfurly, to issue a reminder drivers should "keep in mind stopping distances, especially in adverse conditions. Fog and frosts are common at this time of year."
Four tourists escaped serious injury after the car they were travelling in crashed on SH8 just outside Omarama.
Constable Nayland Smith, of Omarama, said one person had moderate injuries and three others had cuts and scrapes.
He said it appeared the driver "didn't read the road right".
Passengers and those who helped at the Luggate Red Bridge crash said the van was only prevented from plunging several metres into the Clutha River by a steel bridge post.
Detective Alan Lee, of Wanaka, said five females and one male received a range of minor to moderate injuries in the single-vehicle accident that saw the van completely block the bridge from about 7.15am until it was towed away just over an hour later.
The female driver was trapped in the van and cut out by the Luggate Volunteer Fire Brigade.
Two patients were taken by ambulance to the Wanaka Medical Centre for assessment.
The white Mitsubishi L300 van was transporting the six vineyard workers, from Argentina, Scotland, England and Canada, to a Bendigo vineyard and had approached the bridge from the Luggate end.
"The ice on the bridge has been the contributing factor ... it is that time of year," Det Lee said.
Vineyard worker Gonzalo Ortiz (27), a lawyer from Argentina on a working holiday, said he was shaken but not injured.
He recalled the van hitting one side of the bridge and was shocked to see broken wooden railings, snapped wires and bent stays.
"That post saved our lives," he said, indicating the large red steel beam against which the bonnet of the van came to rest.
"I am here with my girlfriend to improve our English and enjoy New Zealand. We are very, very happy. Not because of the accident but because of the ambulance and the fire brigade and the police. They are very, very fast. I can't believe that. It is amazing," Mr Ortiz said.
Constable Dave Felstead said fog and frost covered the Kawarau Gorge yesterday morning.
The gorge is a main transport route for vehicles travelling from Cromwell to Queenstown and Wanaka to Queenstown.
The road was completely shaded by the mountains and frost took longer to melt.
"Drive to the conditions, particularly when it's frosty outside."
