There are fewer and fewer derestricted sections of motorway in Germany.How many accidents do they have on the autobarn in germany with no speed limit. Obviously is speed kills there will be millions on crashes there everyday?
There are also lots of strictly enforced limited sections of motorway, so the Germany argument doesn't really work.
Furthermore, the heavily congested motorway networks around the major cities have limits, either fixed or variable.
Having said that, lane discipline in Germany is not what it used to be, so I'm surprised there aren't more accidents..