How local authorities tackle road gritting as the Met Office issues ice warning

Gritting roads using rock salt :Gritting’ and salting are often used interchangeably when discussing how best to clear pathways after a snowfall but rock salt is the most common method of melting snow and ice during freezing cold days. Rock salt can be combined with grit and spread over roads to provide traction for cars and passersby.

How does gritting de-ice roads? The rock salt within the grit works to lower the freezing point of water, so that ice doesn’t form as quickly on roads and pathways. The level of heat depression depends on the amount of salt being used and how much surface area is being covered. Successfully gritting a road relies on the tyres of vehicles passing through to further spread the salt. Sometimes an anti-caking agent is added to make sure the de-icing salt does not coagulate too much.

Who is responsible for de-icing roads? According to The Railways and Transport Safety Act 2003, highway authorities have a legal responsibility to provide a safe passage along highways, ensuring that roads are not made dangerous by snow and ice, so far as it is reasonably practicable.

When is it best for local and highway authorities to grit roads? Ideally should take place just before temperatures hit sub-zero, just after any rainfall but just before the freezing process begins, as grit spread on the ice needs to then be worked into the slippery surface by moving traffic in order to make it thaw. It is hard to constantly keep track of this small window of opportunity, but daily or weekly weather forecasts often predict when we should expect certain types of weather. This helps when deciding what time it is best to grit roads.

Can the weather become too cold to successfully grit roads? De-icing salt will work on roads, pathways, and driveways to a certain point, usually between minus 8-10 degrees celsius. Below that temperature, roads will still freeze, so it is best to check the weather daily to determine if it is safe to travel to work via car or not. In this instance, local authorities may opt to cover roads in stone grit if they are hardpacked with snow or ice.

Are there any environmental issues that come with gritting roads? By following codes of good practice, local authorities can ensure de-icing salt is used sensibly so that it has a low environmental impact. The effects of salt on vegetation vary depending on species; some are highly tolerant to salt, and some aren’t. Gritters should take care when gritting areas that consist of large vegetation and greenery.

How does ritting Roads affect cars? Vehicles, machinery, and other metal structures that have been exposed to salt should be cleaned regularly, as salt can promote rust. It is best to wash your car after each drive through the snow or ice.

Storing salt: Rock salt is often kept in a grit bin so that it remains dry. It can also be stored in tarpaulin.