How gritting works
We use crushed rock salt to melt ice or prevent it from forming on the roads and this is spread onto the road using six purpose-built gritters. The spreaders at the rear of the gritters are designed to give an even distribution of salt across the road and spread the salt at a controlled rate.
We aim to get salt onto the road surface before the ice is expected to form or snow to fall; this is known as precautionary salting.
Ideally the gritters set off approximately three hours before ice or snow is expected, with each one taking two hours to complete its route. Every effort is made to avoid the need to treat roads during peak traffic periods as the gritters can become delayed in traffic and can get stuck along with the cars, buses and lorries they are trying to help.
How the salt works
Salt is used to prevent ice forming; it does this by reducing the freezing point of moisture already on the road surface. The efficiency of salt becomes less as road temperatures fall towards minus 7°C and below minus 10°C where salting is almost ineffective. It is not immediately effective when spread on top of ice and snow but becomes more effective when traffic has crushed and circulated the salt over the road surface.
Hounslow Highways website
Hounslow Highways
Jubilee House
Depot Road
Hounslow
TW3 1SN
Telephone: 020 8583 2000
