The influence of road surface conditions on traffic accidents is remarkable, especially in snowy countries. And accidents caused by polished ice on the surface of roads are still serious problem in winter. A remote sensing method for road surface conditions will be effective for the reduction of accidents. NIR spectroscopic method was applied for the various surfaces covered in ice and the possibility to detect the friction coefficient was reported on the previous study. In this paper shows the possibility to distinguish the wet road surface from the ice surface covered by thin water. As a result, two incident/reflection angles, 60 degree and 80 degree, are needed and 1500nm wavelength is required set for this method.