We receive daily weather forecasts, specific to Conwy County, throughout the winter, and our aim is to make sure the salt is spread on First Priority Routes before ice forms. The network will be retreated again during the night should prolonged frost or icy conditions have been forecast.
- When snow is forecast First Priority Routes will be pre-salted to keep the highway network open.
- Secondary Priority Routes such as minor roads and estate roads will not normally be salted unless conditions are severe and likely to persist for several days, and then only if resources are available after dealing with First Priority Routes.
- In extreme conditions of heavy snowfall, private and agricultural contractors are employed to help clear the snow.
To effectively remove ice from the road surface the salt requires the action of traffic, which helps the process of breaking down the salt granules into a saline solution. This rapidly melts the ice and prevents further ice forming for several hours.
Situations that can cause problems
No matter how accurate the forecast, there are situations when we cannot salt the network prior to icy conditions. Such situations are:
- When rain is followed by rapidly clearing skies; salting will normally start after the rain has stopped (to avoid the salt being washed away). Sometimes temperatures may fall by as much as 5°C per hour and wet roads may freeze before we have been able to salt them.
- 'Dawn frost' occurs on dry roads when early morning dew develops, falls on a cold road and freezes on impact. It is impossible to forecast accurately where and when this will occur.
- Rush hour snowfall. When rain turns to snow, which sometimes coincides with the rush hour, early salting cannot take place because the rain would wash it away, and gritters may have difficulty in making progress because of traffic congestion.