Abstract
This study deals with road friction in snowy countries in winter, which is one of the major issues in traffic safety, as a first step toward building a forward road friction estimation system. To achieve this purpose, in previous research we proposed a new method that can continuously measure the peak μ in μ-s characteristics and presented measurement results on different road surfaces. Based on these results, in this paper we measured the friction characteristics of snowy and icy surfaces maintained at proving ground, and showed the continuous μ-s characteristics on the surfaces and the peak μ region on each road surface. Furthermore, measurements are taken on ordinary roads under snow-covered conditions, and comparisons with these areas showed that the dynamics of μ-s characteristics should be considered.