We monitor the weather forecast 24 hours a day to ensure that we are ready to grit roads whenever it is needed. We grit roads to try and stop ice forming and we also work to clear snow and ice after it has formed on roads.
There are 737 miles of roads in Wirral and we cannot afford to grit every one of them. So we prioritise 288 miles of well-used major roads and bus routes.
Our fleet of ten gritters spreads a total of 2,100 tonnes of salt in an average winter.
Which roads are gritted?
We spread salt along ten pre-planned routes and each round normally takes three to five hours to complete. When we make the decision to grit we aim to have the first gritter on the road within an hour.
Roads which are gritted are:
- main roads with a lot of traffic
- roads servicing emergency facilities such as hospitals, ambulance services, fire and rescue and police services
- public transport routes and access to stations, bus garages and depots
- roads servicing main industrial and business centres
- known problem areas, for example, significant hills and exposed areas
The M53 motorway is the responsibility of National Highways.
How does gritting work?
When we grit the roads we use trucks to spread salt. Salt helps to melt the ice and therefore clear the roads. This is because the freezing point of water is about 0 degrees so when the temperature drops below this, the water molecules bond together and become a solid (ice).
When we add salt (sodium chloride) to ice, it lowers the freezing point of water and therefore if the temperature drops below 0 degrees, ice is less likely to form.
When the salt melts the ice, the salt molecules (sodium and chloride ions) mix with the water and these make it more difficult for the liquid molecules in water to bond together to form ice. So the higher the concentration of salt, the lower the freezing temperature of water will be.
When temperatures are too cold, the salt can’t get into the structure of the ice to start the dissolving and melting process so it is harder for salt to work.
When we can’t grit
Sometimes there are situations when we can't grit the roads, no matter how accurate the forecast is. For example:
- in certain situations of rain, because rain washes the salt away
- when it has rained and the temperature drops quickly - the wet roads may freeze before we have time to grit them
- when early morning dew falls on a cold road and freezes on impact. It's impossible to forecast where this will happen
- during rush hour, when rain turns to snow. Early gritting can't take place as it would be washed away, and the gritters can't pass through the rush hour traffic. We do grit the roads to remove ice, but this isn't ideal and the grit takes longer to work after ice has formed.
Gritting of other locations
Footways, footpaths, off-road cycleways and public car parks are not gritted as part of the regular rounds. During prolonged periods of ice and snow we may grit some of these areas according to the level of risk.
Grit bins
Grit bins are provided in some streets where regular salting of small areas of footpath and roads is needed. These are for use by the public on public roads and pathways and should not be used on private drives or paths.
Due to limited resources grit bins are refilled once a year at the start of winter.
Clearing snow yourself
There is no law stopping you from clearing snow and ice on the pavement outside your home. The GOV.UK website has some tips to help you do this safely.