We have a computerised Ice Prediction System which gives us the latest weather information as well as actual road surface temperatures and other information from various sensor sites around the County.
Salting is carried out when there is a clear probability of ice or snow, when wet road surfaces are expected to fall to, or below, 0º Celsius.
Whenever snow is forecast we aim to pre-salt all the priority 1 and priority 2 routes prior to it falling. However this is not always possible, for example when it starts as rain and turns to snow. When this occurs salting is delayed until the rain stops in order to prevent the salt from being washed away. This situation can be even more difficult if it occurs during the rush hour as traffic congestion impedes the gritters progress. Once snow has fallen we will continue to work around the clock until all roads are clear. Priority 1 and 2 roads will be cleared first, followed by all other roads, although we sometimes have to return to the priority 1 and 2 roads before all the other roads are clear, to ensure they remain clear of ice and snow. This will often be necessary towards the end of the day, especially when the snow has been thawing all day and evening temperatures fall below freezing causing the melt water to freeze.
During periods of snow we deploy our fleet of 17 gritters equipped with snow ploughs and 3 snow blowers. We also have a network of farmers that we can call on to help clear the roads. However, salt will not instantaneously remove snow or ice. The action of traffic is essential for salting to be effective by breaking down the salt granules to form a saline solution which lowers the freezing point of water.
We give careful consideration to the location and provision of salt bins so as to ensure that the maximum benefit is likely to be obtained.
As a rule, salt bins should only be provided in residential areas adjacent to shopping areas, part way up on hills steeper than 1 in 10 and in other areas where both need and usage can be demonstrated which are not included on precautionary salting routes.