A police spokeswoman said the crashes ranged from cars sliding into other vehicles, fences and lamp-posts through to more serious accidents yesterday morning.
Quick thinking was believed to have prevented critical injuries in a crash in Henley caused by black ice.
Sergeant Matt Lee, of Dunedin, said a 39-year-old man was driving south in Allanton-Waihola Rd (State Highway1) about 5.15am yesterday when he lost control on black ice on the Taieri River bridge.
The vehicle spun and hit the barrier, knocking out concrete columns.
A 50-year-old man driving a truck, also heading south, took evasive action.
The truck still hit the van, but critical injuries were believed to have been avoided thanks to the man’s manoeuvre.
The driver of the van called emergency services and was trapped in the vehicle until they arrived.
Both lanes were blocked, but reopened about 9am.
It was suspected at least one passenger had a leg injury, Sgt Lee said.
A St John spokesman said four people were treated and transported to Dunedin Hospital.
One patient had serious injuries, two had moderate injuries and one had minor injuries, he said.
There was another crash in the same road at 11.50pm the night before.
Sgt Lee said a 25-year-old man escaped injury after his vehicle slid on ice on the bridge and hit a barrier.
Two ambulances, two rapid response vehicles and one helicopter responded, a St John spokeswoman said.
One patient was taken to Dunedin Hospital by helicopter in a serious condition and two people were taken by road in a moderate condition.
A Dunedin City Council spokesman said contractors worked through the night gritting, sweeping and ploughing streets.
The Otago Regional Council suspended bus services on Monday night because of dangerous conditions and yesterday morning hill suburb services remained significantly affected.
Blueskin Bay community emergency response co-ordinator Mandy Mayhem-Bullock said about about 15 travellers stayed at the Waitati Hall overnight after the Northern Motorway was closed.
More travellers were offered assistance but stayed in their vehicles, including a bus containing about 50 people.
Many of the travellers were students returning from mid-semester break, Ms Mayhem-Bullock said.
Additional reporting staff reporters
