About 25% of roads in the county are currently pre-gritted
Durham County Council says it may have to further reduce gritting operations because it is struggling to obtain additional salt supplies.
Only 25% of the county's routes, or all A and B roads, are being pre-treated - down from 45%.
The authority said the figure was in line with national guidance, but has warned even fewer roads could be pre-gritted if the cold weather continued.
Such a decision would be "last resort", it stressed.
Pre-salting the county's A and B roads requires a minimum of 300 tonnes per day, according to the council.
In severe conditions, this rises to 1,000 tonnes. Current stocks stand at less than 3,000 tonnes.
Terry Collins, director of neighbourhoods, said: "I want everyone to know that this decision will not be taken lightly.
"Last week I appealed directly to the Department for Transport (DfT) to review our case for more supplies.
"I put forward, in the strongest terms, the council's special geography and scattered rural communities, but I am advised the national shortage means increasing our deliveries is not an option."
In December, the North East Ambulance Service (NEAS) complained that crews were being hampered because some County Durham roads had not been gritted.
However, it later issued an apology and said it accepted that main routes had been treated.