Friction measurement changes not only with testing method and pavement surface type but also with uncontrollable climate variables, one of which is temperature. Temperature affects friction properties because it changes the physical properties of tire rubber and asphalt pavement surfaces, which are both viscoelastic materials. Seasonal variation of pavement friction has long been noticed in the field by researchers (22). The general trend of the variation is that skid resistance decreases during seasons with warmer temperatures and increases during seasons with colder temperatures (23). These variations should be considered when comparing test results measured from different pavement surfaces.