Just been driving down a national speed limit (60mph) road.Less than 1cm of snow. No ice, nothing. Could probably do a ton down it actually, if it were legal so to do.Yet virtually everybody seems to be crawling around at 15mph and taking about 30 seconds to get around every junction corner.What is it with people? Genuinely, what is the psychological explanation for everybody to start driving like complete muppets just because of an unexceptional change in the weather?