Is it safe to drive Germany, Austria, Hungary, Czech Republic in December?

I am planning to travel to Europe in December 2011, I plan to go to cities like: Frankfurt, Berlin, Prague, Vienna, Budapest, Zurich, Milan, Paris, etc. I will rent a car and drive all the way, and I know that most European highways are very safe, but I would want to know if "snow" will be a problem for this travel. I don't know how common is to have snow in December (December 10 to 27), please if someone have been in these highways in December please let me know your experience. Thanks!!