Black ice, sometimes called clear ice, is a coating of glaze ice on a surface, for example on streets or on lakes. The ice itself is not black, but visually transparent, allowing the often black road below to be seen through it and light to be transmitted. The typically low levels of noticeable ice pellets, snow, or sleet surrounding black ice means that areas of the ice are often next to invisible to drivers or people walking on it. Thus, there is a risk of slippage and subsequent accident due to the unexpected loss of traction.