Improvement of the de-icing on the roads at Kittilä, Muonio, Enontekiö, Inari and Utsjoki

This report examines the winter drainage methods of roads in cold climates in order to reduce road maintenance problems caused by icing. In summer, the precipitation flows on the surface, and a small proportion infiltrates into groundwater. In winter, the precipitation is accumulated on the ground surface as snow. The unfrozen groundwater, and also some surface water continue flowing also in winter. If the flow conditions are limited, unfrozen water tends to be forced to the surface, and it freezes according to the cooling conditions, causing safety problems to the road traffic and flooding during springmelt, when flow channels are filled with ice. The limiting factors may be excessive ice formation in the watercourse, or deep frost penetration, reaching the groundwater table. Practical solutions to mitigate icing problems are presented and discussed.