A good compensation model for regulating costs for winter road maintenance between client and contractor requires two well-functioning sub models: (1) a sub model that describes the weather during the winter season; and (2) a sub model that links the weather descriptions to the need to take measures/set in resources. The basis for the weather descriptions are data collected from the individual stations in the Swedish National Road Administration system for road weather information, RWiS. Through using special definitions, the data are translated into eight weather situations at an hourly level. Examples of weather situations are snowfall, drifting snow and risk of slipperiness caused by rain or sleet on a cold roadway. The hour-by-hour weather descriptions are then summarised into clearly defined weather occurrences, for instance drifting snow during 6 hours or a snowfall lasting 20 hours with a snow depth of 10 cm. The final result of weather descriptions for a winter is a number of clearly defined weather occurrences. The compensation model is based on the number of weather occurrences for each RWiS station chosen as representative for a certain maintenance area. Starting from each weather occurrence the number of so-called resultant weathers is calculated being the basis of compensation. In this step the connection is made between weather and the need to take measures. (Author/publisher)
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