"If you slide on the ice, you're not going to stop and you're going to crash into other vehicles," Snr Sgt Bond said.
Officers also attended a crash in Malvern St about 7.30am.
A mother with two daughters in her car came around a corner, slid on black ice and crashed into two parked cars. A car driven by a 19-year-old woman then came around the corner, travelling east.
She braked ahead of the initial crash scene, and veered across to the other side of the road, hitting a fence at a building site.
The first woman was breath-tested and recorded a breath alcohol level of 701mcg, Snr Sgt Bond said.
The legal breath alcohol limit for adult drivers is 250mcg.
Shaded areas of town tended not to defrost in cold weather and were icy, particularly in the mornings, he said.
A total of seven frosty morning crashes were attended by police, Snr Sgt Bond said, including one in Maori Rd at 10.40am.
A car driven by an 85-year-old woman slid on ice and went down a bank.
She was taken to hospital as a precaution, but only received a small cut to her head, Snr Sgt Bond said.
Another happened at 10.20am when 20-year-old man was driving too fast for the conditions, Snr Sgt Bond said.
His car fishtailed, crossed the centre-line and crashed into another vehicle in George St, near Willowbank Dairy.
No major injuries were reported but passengers were taken to hospital as a precaution.
