After the war West Germany abolished the speed limits. The West German car and motorist lobbies were powerful, the speed limits were seen as a relic of the Nazi past and following the experiences with the centralised Nazi state devolution to states were seen as a safeguard against the federal government becoming too powerful and tyrannic.

Suffice to say, germany after the war was still in large part run by the nazis and for some weird reason, I just can't imagine why, they didn't bother repelling any of the other traffic laws the nazis made which, I know this will come as a surprise, were explicitly made to encourage car traffic and discourage any other mode of transportation.