Slippery roads created by snow and ice cause the most dangerous driving conditions many of us are likely to face. Which is why up and down the country fleets of gritter lorries are out de-icing roads and keeping them clear and safe to drive on.
Rock salt is widely used throughout the UK to keep our roads safe and moving during cold weather. In this blog post, we highlight many of the key benefits of using rock salt for de-icing.
Why is salt used to de-ice roads?
Although you may often hear the terms grit and gritting, in most instances the substance that you see being spread on roads in the UK is rock salt.
Rock salt is ideal for this purpose because it lowers the freezing point of water significantly and is therefore able to melt ice and snow. This quality also means that salt can be used as a pre-treatment that prevents ice from forming and makes it easier for any snow that falls to be cleared. Rock salt will work in this way in temperatures up to approximately -10oC, which means it is an ideal solution in most weather conditions experienced in the UK.
In addition to de-icing road surfaces, rock salt also improves driving conditions by providing traction for tyres on icy surfaces, reducing the risk of skidding and road traffic accidents.
Rock salt is also widely used to keep pedestrian routes, car parks and driveways clear of ice.
What are the benefits of using salt to de-ice roads?
Of course, the first benefit of using salt to de-ice roads is its effectiveness but there are also a number of other reasons why it’s so often the de-icer of choice.
Rock salt is readily available in the UK, with three main mines providing most of the country’s supply, which makes it a cheap and accessible resource.
The DfT estimates that the welfare cost of disruption to domestic transport is around £280m per day in England and the direct economic costs amount to £130m per day.
Since salt can be stored easily and for very long periods of time without losing its melting capabilities, it is viable for local authorities to stockpile the salt that will be needed over the winter months so that they are well prepared to deploy gritters when it is necessary. It is also relatively easy to spread, which allows a prompt and effective response when outside temperatures drop.
What is the environmental impact of de-icing salt?
Rock salt is a non-toxic, natural and sustainable resource that is readily available, meaning that there is no need for road de-icing products to be imported from outside of the country.
Salt should be used responsibly, following codes of good practice, to ensure that its use has a low environmental impact. Residual salt is gradually diluted and disposed of through natural processes and effective planning is used to ensure that salt does not run off the roads into water courses. Winter maintenance vehicles are also equipped with technology that allows the right amount of salt to be spread on the road surface and the rate at which the salt is spread can be adjusted based on road conditions.
So, next time you see a gritter out and about remember that rock salt plays an important role in keeping our roads open, safe and moving.