The sight of gritters on the road in recent hot weather has caused some confusion.
They may be a familiar sight in the depths of winter as they try to keep the roads free of ice and snow, but gritting isn't only effective in colder months.
The treatment can also stop tarmac from melting, which is why gritting lorries are also seen out and about in hot weather.
Temperatures in North Wales reached up to 30 degrees earlier this month amid a "mini-heatwave" in the UK.
ITV weather presenter Ruth Dodsworth explained the use of gritters in summer to people confused by the sight of the vehicles on the roads.
She wrote on Twitter: "Salt is also used when roads are at risk of melting during scorching weather.
"Spreading salt on the roads helps to stabilise the road surface by absorbing bitumen."
Tarmac can begin to soften when roads reach temperatures of around 50C, which can happen as the dark surface of the road absorbs heat and increases in temperature during the day.
