Winter Friction Project in Norway

The Winter Friction Project in Norway deals with practical, technical, and economic problems arising in providing good friction on winter roads. One of the main activities throughout the whole project period will be to carry out field studies, which will consist of (a) a testing program (scientific studies) to document performance of different friction improvement methods and (b) a follow-up study on roads in 10 counties to document existing winter maintenance practice on both salted and sanded roads. Scientific studies during the 1998–1999 winter season revealed that new measures carried out with sanding methods last longer than do traditional sanding methods. Although the effect of using cold and dry sand can disappear after the passage of 50 vehicles, it has been proved that by using heated materials or adding warm water to the sand it is possible to maintain a friction level above the standard, even after the passage of 2,000 vehicles. In particular, a method using a mix of hot water and sand showed promising results. During summer and autumn 1999, the warm-wetted sanding method was further improved by development of two new Norwegian prototypes. These new spreaders have been tested together with alternative ways of adding water (type of spreader and temperature of the water). Wet sand has been compared with traditional sanding using dry materials. The field tests carried out during the winter season 1999–2000 with wet sand and roller distributor confirm the results from last season. Good results were achieved with the Norwegian trucks.