Further black ice warning

Traffic comes to a halt on the Northern Motorway yesterday morning after a crash involving a ute, a petrol tanker, a car and a bus. Photos by Stephen Jaquiery.

Icy road conditions which made driving and walking in Dunedin treacherous in many places yesterday were re-emerging last night.

Photos: Slipping and sliding in the ice

Police again reminded motorists to drive to the conditions as at least four motorists crashed in black ice last night.

Single vehicle crashes on Three Mile Hill Rd and Pine Hill Rd and two on the Northern Motorway prompted police to call for council contractors to grit the sections of road.

No-one was hurt in the crashes, Senior Sergeant Brian Benn, of Dunedin, said.

Ice was a factor in at least five vehicle crashes earlier yesterday, and about 10 people visited Dunedin Hospital's emergency department with injuries sustained after falling on ice.

Southern District Health Board patient services executive director Lexie O'Shea said staff treated head and fall injuries, and lower limb fractures.

However, the icy conditions did not affect hospital staff availability or service provision, she said.

MetService meteorologist Elke Louw said temperatures were not as cold as forecast, with Queenstown down to -5degC instead of the predicted -13degC, but were still below freezing in inland areas.

Yesterday's respite from rain and snow was forecast to end tonight, with more snow showers and rain expected, she said.

In preparation for the ice, Dunedin City Council contractors spread more than 100 tonnes of grit on roads - 30 tonnes was the average for a frosty day.

''It didn't get as low as we thought, but we did it just in case. It's a hard thing to call,'' council roading maintenance engineer Peter Standring said.

The main focus was getting traffic across and down the city's hills and on to ''feeder routes''.

Grit could not be spread on everyone's streets, he said.

Use of the council's webcams was extensive, indicating more people were checking conditions before travelling, he said.

New Zealand Transport Agency coastal Otago maintenance contract manager Nick Rodger said grit and de-icing material were spread on the main highways in anticipation of the frost.

The past two days were the first real winter event of the year so people needed to remember how to drive in such conditions, he said.

''Grit is not a substitute for a dry road.''

Drivers needed to slow down and increase their following distances, he said.

State Highway 87 from Outram to Middlemarch was opened about 2pm yesterday after contractors had cleared snow.

The icy conditions, combined with crashes, caused delays and deviations to some bus routes.

Go Bus operations director Nigel Piper said while all services operated, some drivers were unable to complete their trips.

''Where there wasn't grit to aid traction, we didn't go into them [streets] because of safety concerns.''

Ritchies Transport Otago regional manager Malcolm Budd said staff checked urban runs in a four-wheel drive vehicle before buses were released.

Hill suburb services did not start until 10am.

Many schools had a delayed start and selected city council sports grounds were open for senior games and training.

Chilly start
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Coldest South Island temperature -7degC at Pukaki