This is a proposal for tagging piste segments that do not exist in summer (without snow) and thus there is no better highway=* tagging. As such this applies to ways only. For mapping ski/snowshoes/... routes (regularly used lines of travel consisting of several ways) use the relation route=piste (alternatively route=ski).
Having a unified tagging of winter-only ways is important to have them rendered in winter maps and have them included in GPS data sets.
--Kaspi 10:10, 25 February 2012 (UTC)