I.down1[美 daʊn, 英 daʊn]副down often appears as the second element of certain verb structures in English (back down, clamp down, tone down, etc). For translations, see the relevant verb entry (back, clamp, tone, etc).
But not even four-by-four police vehicles -- and certainly not their cruisers -- could get down many roads rendered impassable by the biting winds and blasting snow.