The Walloon Region's climatology is very complex as a result of its variable geographic features, the very weak influence of maritime airstreams and an exposure to southwest prevailing winds. That is why road surface temperature forecasts are not sufficient to assess the danger over the whole length of the road network. To compensate for the spatial inaccuracy of road surface temperature forecasting, a thermal mapping programme was set up to enable the decision-makers to get a visual display of temperature evolution on the slow lane. This very accurate tool offers the following advantages to the to the managers: (1) Planning the watch rotations of the co-ordinators and the network controllers; (2) Planning the time of optimal salting just before danger appears; and (3) Planning more localised salting operations and making savings on salt quantities. Nevertheless, the drawbacks are not inconsiderable: (1) Because of the accumulation of errors in measurements carried out near the stations, weather forecasts, thermal fingerprints, choice of weather type and cartography, thermal maps sometimes do not reflect reality any more. This can be noticed particularly when using thermal maps predicting temperatures at the end of the night in case of an intermediate weather type; and (2) Although thermal mapping proves very accurate, it does not always confirm the decision to spread salt. The winter serviceability co-ordinators very often face situations where road surface temperature on a given circuit makes them have doubts as to the necessity of spreading salt. Thermal mapping only shows road surface temperatures. It goes without saying that relative air humidity and precipitation risks must be taken into account. That is why the local terminal data are analysed and the network is subjected to control. This tool still has to be perfected and its predictions made more useful. It should also integrate levels of service in support of a legal decision-making methodology.