As usual route planners are based on the principle of travel time minimization, the travel speed and distance from the destination are two key factors to calculate the optimal route. Current systems are based on predetermined speed limits stored on road maps. However, few of the systems used today, consider current environmental influences. The aim of this thesis is to examine the extent of route changes for MIT (Motorized Individual Transport), when weather-related speed reductions are considered. The basis for the work are road data from OpenStreetMap and historical weather data in the NetCDF (Network Common Data Format) provided by the company Ubimet. The data is processed, by using the ArcGIS software from ESRI (Environmental Systems Research Institute, Inc). The study area corresponds to the territory of Austria. After the treatment of roads and weather information, the records are processed, using the software, to weather-related road networks. This is done by two different methods, static and dynamic. The static model concerns the routing behaviour using a specific weather situation, while the dynamic model takes temporal change of the weather into account. For the analysis of the new, influenced by the weather, routing behaviour the created routes at times of strong weathering are compared with predetermined reference cases without considering the weather. Routes referring to periods of normal and strong weathering, e.g. heavy rain, are analysed and compared in travel time, route length and exposure to adverse weather conditions.