GRITFO – It’s set to stay cold this week folks
Ever wondered how gritting decisions are made? Tonight’s video (Tuesday, January 6) follows one of our winter duty officers - Lewis - explaining the careful monitoring and inspections involved in deciding when and how much grit we need. He's one of our project engineers and does this extra role with a few others in the early hours to make sure we have cover.
Our gritting trucks were out from 3am this morning, spreading more than 80 tonnes of salt across 400km (250 miles) of roads, footpaths and car parks, following inspections at 2am.
Gritting is just the start of the de icing process – traffic helps activate the salt. That’s why early morning drivers may still encounter icy roads, especially when traffic levels are low.
The Dirt on Grit
There is no grit!What you see coming out of the lorries is rock salt. “Gritting” is the common term for spreading rock salt on our roads.
It works better on large road surfaces
It doesn’t clog drains like stones would
Rock salt lowers the freezing point of water, reducing the chance of ice and frost forming
Above freezing? We still grit.Even if the air feels mild, road surfaces can be much colder – especially on 
bridges and in exposed areas.
bridges and in exposed areas.
Engineers monitor road surface temperatures (and a load of other data) not just the air, because that’s what determines whether ice will form.
Behind the scenes, gritting is a science. Crews rely on:
weather forecasting
Road sensors
Careful timing based on highly localised road surface data
Plus physical road inspections at 2am 