Gritting - questions and answers

We base our decision to grit, or not grit, on the forecasts provided by MetDesk, who provide all winter service forecasting for all GM Authorities. This forecast, received on a daily basis, gives predictions of the possibility of freezing road temperatures, snow and other weather conditions.

We aim to complete the gritting routes before the road surface temperature drops below freezing. Gritting routes typically takes 5 hours to complete. The first hour allows for calling out the gritting crews from standby and then 4 hours to complete the gritting

• Check treated roads and streets

We only provide salt bins at known trouble spots, such as dangerous bends and steep hills, where snow and ice have caused serious problems in the past. We review the locations annually and where we position the salt bins takes into account the impact on the locality and the ease of access for re-filling. By the time the Winter Service comes into operation at the beginning of November salt bin locations have already been decided.

Salt bins are only provided where we think they are really needed. They are not provided on gritting routes. We have to limit the number of bins we provide so that we are able to maintain and re-fill them at times of need. There are around 300 salt bins across the borough.

• Check salt bin locations

During very severe weather conditions, when snow or ice may remain for some days, we consider treating some public footways providing that all priority gritting routes are clear and we have sufficient resources available. Where this is the case we give priority to treating the following.

• Primary shopping centres.
• Secondary shopping centres.
• Link car parks to primary shopping centres.
• Link car parks to secondary shopping centres.
• Public buildings (including offices, leisure centres, libraries, etc).
• Elderly persons homes.
• Safer routes to schools.
• Police stations.
• Health centres.
• Stairs and inclines leading from subways.

Check treated footways

Despite the high level of service provided, no guarantee can be given that treated roads will always be completely clear of ice or snow. This can be for various reasons. Some examples are provided below:

• It takes time for the salt to become effective after roads are salted.
• Rain and running water can wash salt off roads leaving them prone to re-icing.
• In severe cold weather (below -5°C) even salt will not prevent roads from icing.
• If freezing conditions follow rain, salting will normally start after the rain has stopped to avoid salt being washed away. Temperatures may fall by as much as 5°C per hour and the wet roads may well freeze before the gritter has been able to salt them.
• Dawn frost occurs on dry roads where early morning dew falls on cold road surfaces and freezes on impact. It is impossible to forecast with any accuracy where and when this may happen.
• When rain turns to snow during busy times, early salting is washed away and gritters are unable make progress due to traffic congestion.
• Over a full season, weather forecasts are approximately 90 percent accurate. In most winters, this means that there are several days when a road frost is not forecast but still occurs.
• Treated roads can, therefore, still have icy patches and drivers should remain vigilant and aware of the need to drive with due care at all times, especially when road frosts or freezing temperatures follow rain.

• Visit the Met Office website for the latest information about weather conditions and predictions.
• Visit the Met Office Get Ready for Winter website for useful advice on preparing for winter.