There are many conceiveable applications for efficient models of road conditions both on an overall level, i.e. macromodels, and on a detailed level, micromodels. The following are examples of such applications: 1) Producing reports on average road conditions in a road network over a period of one winter; 2) Providing an alternative to costly manual surveys of road conditions, and 3) Applying relations between road conditions and effects on road users in calculating a standard of winter road management which is optimal in regard to the public economy. The report begins by describing present knowledge and experience partly from surveys of road conditions with various levels of detail, partly from two models, a Swedish levels of detail, partly from two models, a Swedish macromodel and a Norwegian micromodel. On the basis of this experience, the bulletin presents a philosophy for designing a micromodel of high quality. This is followed by a list of various factors, or variables, that influence road conditions. A total of 34 variables have been examined. Of these, 24 are considered to exert a strong influence on road conditions and 7 moderate influence. After a description of possible methods and instruments for the field measurements which are to furnish detailed data for designing the model, the report concludes with a proposal for stage 1 in the development of a micromodel of road conditions. (A)
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