Five Northamptonshire roads which saw 11 separate accidents caused by drivers skidding on black ice were not gritted the night before.
The first cold night of winter last week meant black ice covered many Northamptonshire roads on the morning last Friday morning (November 29).
Between 7am and 9am that morning, 11 vehicles across the county left the road after skidding on ice and crashing. Some ended up in ditches and one ended in a three-car collision.
All of the roads with accidents - including Newport Pagnell Road, Roman Road and West Haddon Road - are on the county council's precautionary gritting route.
But it is now understood that Northamptonshire County Council's Highways Team did not grit these roads on Thursday night because weather forecasts first showed that temperatures on those roads would not drop below 0.5C.
The council says cloud cover changed overnight and led to the cold snap.
Incredibly, no one was hurt in any of the 11 separate crashes across the county on Friday morning.
It comes after some budget proposals for 2020/2010 last month announced £500,000 would be "saved" from the winter budget in pursuit of a real-time system that deploys gritters as the weather shifts.
A spokesman for Northamptonshire County Council said: “Like the majority of councils with responsibility for highways, Northamptonshire runs a route-based forecasting system, which allows it to grit individual routes rather than an entire network.
“We would always advise that drivers should never assume that a road has been gritted and should drive with caution when there has been a frost. Because a road has been gritted it does not mean that all risk of accident has been eliminated.”
Northamptonshire currently operates a 'precautionary' gritting route system, which means the county's most-used roads are salted if weather forecasts say temperatures will drop to 0.5C or below.
It is moving towards a 'route-based forecasting' system that will have roads gritted as-and-when the weather predicts freezing weather.
Other major roads like the M1, A14, A45 and the A5 are gritted by Highways England.
The spokesman said: “The current gritting routes cover a relatively high proportion, 43 per cent, of the county’s roads and we will be reviewing and optimizing the route plan as part of the best practice exercise.
“By being smarter about the way we carry out winter maintenance we can bring about this saving.