Oh, another tidbit of info for the OP...Between some countries (Germany and France comes to mind), the actual border crossings still have gate shacks, so to speak, but they are largely unmanned. I have crossed into France from Germany and saw that the French police (I think) were stopping cars leaving France and spot checking them. This may have been tax police or some other entity. I also remember seeing these border booths going from Luxembourg into Belgium. Germany to Austria, on the other hand, has only a sign.

There are border crossings going into Switzerland, and they are all manned (or were a couple of years ago).