Police want drivers in the southern South Island to stay off the roads tonight if they can possibly do so.
Large patches of black ice are making for dangerous conditions in many parts of Central Otago, Southland and Waitaki.
Police say there have been several crashes during the afternoon.
Police warn motorists who have to travel tonight to keep to an appropriate speed for the conditions - and to be patient if they find themselves behind vehicles safely travelling slowly.
Take your Radio, Podcasts and Music with you