I may seem to be a bit obsessed with the weather and its effect on the roads at the moment but you have to realise I walk to and from work about 4 times a day so  spend a lot of time thinking about it. When its pure water ice there is so little friction that its simply impossible to walk unless the road is completely flat (not common in Norway). The only hope is that the council has spread some grit on the surface and this make an incredible difference, even just a few grains. I suppose its because the pressure under a few grains will cause them to really bite into the ice. Might be interesting to study the relationship between the number of grains and the frictional force. Pity EE's don't start until after Easter.