Winter gritting

False

Spreading salt on the road is only the start of the de-icing process. Movement of salt around the road by traffic is essential to complete the process. Overnight, when traffic levels are low, roads can remain icy for some time and people should take care.

False

Salt works by lowering the freezing temperature of water. This prevents ice or frost forming on the roads as it would otherwise, once the temperature of the road surface falls to 0°C. Salt usually loses its effectiveness once the temperature falls below -5°C and stops working at -10°C. Pre-salting the road forms a separating layer so if snow falls it doesn't freeze onto the road surface and can be ploughed off or churned off by traffic.

False

Salt only effectively melts snow when as much of it as possible is removed and traffic can move the salt around. To protect the road surface from ploughs we remove snow to around a depth of 20mm before spreading salt.

False

In the concentrations we use on our roads salt does not melt ice below minus 8°C and is less effective at temperatures below minus 5°C.

False

Anyone can clear snow and ice from the pavement outside their home or public spaces to prevent slips and falls - normal table salt will work. Don't be put off clearing paths because you're afraid someone will get injured. Remember, people walking on snow and ice have a responsibility to be careful themselves. To clear snow and ice safely, follow advice from the Met Office.

Salt no longer sprays in all directions, covering the windscreens of cars and the legs of pedestrians. Computer-controlled mechanics now dispense the required amount of salt directly down onto the road. They can also 'throw' the salt to one side or the other to ensure the whole carriageway is covered even if the vehicle is driving down one side only.

However, this is not always a myth as the vehicle may not have reached the starting point of its treatment route, or maybe returning to the depot at the end of its route or to refill.