Om Torbjörn Gustavsson
Formation of slipperiness Detailed measurements of climatological parameters in close connection to the road surface give the background for analysis of the processes that are important for formation of slipperiness during different weather conditions. Accurate instruments are used and placed at different levels above and below the road surface for coverage of the relative importance of temperature, humidity and wind. As a compliment IR-recordings are used for detailed measurements of the road surface temperature.
The resulting friction from different weather scenarios is also analysed in order to link the information from RWIS-stations to what actually is happening on the roads. This is very important knowledge to be able to give accurate warnings and information both to maintenance personal and to other users.
Winter indexes Winter index is a technique used in road climatology for relating cost of winter maintenance to statistics regarding weather and road slipperiness. Important research aspects are – which parameters to include in the index, definition of variables when it comes to duration and extension as well as link the weather parameters to actual need of maintenance on the roads.
Indexes are also developed in order to be used as a reference material for field station location and selection of equipment to be used at the stations. This has been shown to be a very useful complement to ordinary thermal mappings.
Information to drivers A very important research area within road climatology is to extend the use of RWIS-data. The system is originally developed to give information to maintenance personal regarding the needs for salting and plowing. However as the system has been expanded and developed the next phase has been made possible. This implies giving information directly to the road users about severity and hazardous road weather conditions. Research and development is carried out in order to develop models that use RWIS-data, thermal mappings and topoclimatological analyse for presentation of valuable information to road users regarding the prevailing conditions.
Modelling of climate - Projecting of new roads. The research in this part aims at adapting the local climatological model at the projecting stage of different applications where topoclimate is important to consider. By this adaptation it is possible to calculate the local variation in temperature associated with different elements in the landscape. When planning new roads it is possible to use this knowledge as a tool for comparing different alternatives of routes with respect of risk of slipperiness. The LCM is used together with a geographical information system and temperature variations are calculated for different areas in respect of weather conditions. Statistical information about meteorological conditions is obtained from synoptic weather stations and integrated in the analyse. A study from an area on the Swedish west coast is presented in the paper "GIS as a tool for planning new roads in respect of climatological factors" and a further application will be in connection with calculation of indices for classification of winter climate.
Topoclimate The topoclimatological research focuses on the nocturnal cooling and development of temperature variations in complex terrain. Two approaches are used modelling of temperature development and extensive field measurements of the existing temperature pattern. The modelling part aims at determining the relative importance of cold air drainage in valleys regarding the establishment of temperature variations. The measurements on the other hand aim at detecting and analysing the processes acting in different environments. By combining these two parts it will be possible to link the processes acting in different scales and environments and their relative influence on temperature variations.
The road climatology group works together with several national and international partners. These projects have a focus on solutions for detecting and giving warnings about severe weather conditions along roads. Cooperation is made both with authorities, companies and universities. Please have a look at following links for further information:
Modeling Road Surface Temperature from Air Temperature and Geographical Parameters-Implication for the Application of Floating Car Data in a Road Weather Forecast
On the relationship between the risk of hoar frost on roads and a changing climate in
Winter hoar frost conditions on Swedish roads in a warming
The use of screening effects in modelling route-based daytime road surface
Road Surface Wetness Variations: Measurements and Effects for Winter Road
Ice formation detection on road surfaces using infrared
Geographical distribution of road slipperiness in Sweden - National, Regional and County
Information not data - future development of road weather information
Klimatförändringar - naturliga och antropogena
A road climate study in China - using winter index
VViS-data som underlag för beräkning av väglagsfördelning och
An attempt to define the Road Climate
The applicability of similarity theory to a road