According to the local highways council spokesman, road salt/grit will only 'melt' snow and ice accumulations on the road where temperatures are less than minus 8 degrees. Any lower, and the salt has no effect.
The only thing that would have a direct effect on the frozen snow accumulations was direct warm sunshine, but don't go breaking out the sun cream just yet.
Note: Everyone at Home Improvement Quotes would like to pass on their sincere thanks to all the Gritting teams that had to venture out in appalling conditions and kept our roads as clear as they did. Thanks Guys!
photo credit: dan slee