A spokeswoman said police were called to the crash scene on Queens Flat bridge shortly after midnight last Saturday.
No-one was there when police arrived, she said, but inquiries established the driver of the car had been taken to hospital with minor injuries.
Police then advised the Waitaki District Council a grit truck was required and the road was subsequently gritted.
A council spokeswoman said the road was gritted last Friday as the forecast indicated frosts over the weekend.
The road was actively maintained.
"It is gritted before forecast events and when we receive customer requests when a frost has occurred out of the blue."
She said roads were selected to be gritted based on experience, areas of noticeable shade, and customer feedback.
Residents have long said the council was not keeping the road sufficiently gritted.
Helen Kay, of Ngapara, said there had been as issue with the amount of grit on the road since SouthRoads became the contractor.
She believed it was only a matter of time before someone died in a crash at the site and when that happened she would support their family members in a court case against the council.
"It’s negligence. They know the problem is there and it is negligence. They’ve had loads of reports."
In 2014 her Subaru Impreza left the road and became submerged in a nearby pond.
Miss Kay and other residents called for more grit to be used in June this year.
"I actually cried when I saw that car down there. It’s so frustrating. Why won’t they listen?"
A SouthRoads spokesman said he could not comment as the council was responsible for statements to media.
Council road manager Michael Voss said the council took road safety very seriously and took precautions to keep motorists safe, including the use of grit.
"Too much grit has a reverse effect in that tyres can roll over the top and lose traction, hence we are careful over the amount applied and not over-grit. When necessary, we also use temporary speed restrictions and caution motorists to drive to the conditions."
