Autobahn is a slur used to describe German in a derogatory way. German for freeway. Refers to the idea that Adolf Hitler build the autobahn for war.
The word Autobahn is a racial slur that has been used historically to degrade and dehumanize german. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to german. If you are unsure about whether or not it is appropriate to use the word Autobahn, it is best to err on the side of caution and avoid using it in any situation.