Emergency services were called to twin incidents on the same stretch of Clutha Valley Rd, about 6km north of Balclutha, at 8.50am.
Balclutha police said a blue Nissan Navara with a single occupant, heading towards Clydevale, had left the road first, followed almost immediately by a white Toyota Hiace work van occupied by two men.
The incidents appeared to be unconnected, although police said both were likely due to black ice, which was seen by a reporter at the scene.
None of the occupants were seriously injured, and all three were able to walk unaided from their vehicles before assessment by paramedics.
A police spokesman praised the owners of the work van for additional safety features, which he said had helped prevent a more serious incident.
"The owners have installed a safety barrier between the cab and rear of the vehicle, which has both prevented crushing of the cab, and items from the rear of the van from entering the cab during the incident.
"Given the outcome here, it’s something other companies should perhaps consider for their fleets."
He said despite recent hard morning frosts, incidents involving "black ice" were lower than expected now for South Otago.
"Touch wood, we just need people to take extra care and stay safe. Slow down, and drive to the conditions."
