Roads that are safe in all weathers are a prerequisite of modern society, and large amounts of money have to be spent, especially in winter, by highway authorities to make travel safe. Climatic factors like fog frequency have to be taken into account in planning the route that a road will follow. The operation and maintenance of the road network requires that weather information be taken into account if measures like preventative salting and top dressing are to be successfully carried out. Particularly in the field of winter maintenance of highways a range of new technology has recently...