by Jayne Glass
The news in late 2010 has been all about ‘the big freeze’. Heavy snow has been falling across the UK earlier than normal, with some devastating effects. Usually, local councils work to keep the roads and pavements clear by spreading salt/grit. But despite attempts to stockpile salt ahead of this winter, some councils are already running low. In Powys, Carmarthenshire and Caerphilly, councils have already used at least a quarter of their stock, and across Wales 15% of the salt supply has gone.
In 2008, John Thornes and Lee Chapman focussed on decision-making for salt spreading, in an article in Geography Compass. Although the use of weather information systems for the winter maintenance of roads is now widespread, observations and predictions are often only available for a limited number of road sensor sites in a region. Thornes and Chapman carried out a winter-long trial of the XRWIS road weather information system in Devon. They found that up to 78 salting runs on 6 salting routes could have been prevented. This would have saved up to £80,000 in labour and materials. There is also scope for this system to be applied to prediction of low rail adhesion on the national rail network.