<P> The Autobahn (German: Autobahn (ˈʔau̯. to:. ba: n), plural Autobahnen) is the federal controlled - access highway system in Germany . The official German term is Bundesautobahn (plural Bundesautobahnen, abbreviated BAB), which translates as "federal motorway". The literal meaning of the word Bundesautobahn is "Federal Auto (mobile) Track". </P> <P> German autobahns have no federally mandated speed limit for some classes of vehicles . However limits are posted (and enforced) in areas that are urbanized, substandard, accident - prone, or under construction . On speed - unrestricted stretches, an advisory speed limit (Richtgeschwindigkeit) of 130 kilometres per hour (81 mph) applies . While going faster is not illegal as such in the absence of a speed limit, it can cause an increased liability in the case of an accident; courts have ruled that an "ideal driver" who is exempt from absolute liability for "inevitable" tort under the law would not exceed Richtgeschwindigkeit . </P> <P> A 2008 estimate reported that 52% of the autobahn network had only the advisory speed limit, 15% had temporary speed limits due to weather or traffic conditions, and 33% had permanent speed limits . Measurements from the German State of Brandenburg in 2006 showed average speeds of 142 km / h (88 mph) on a 6 - lane section of autobahn in free - flowing conditions . </P> <P> Germany's autobahn network has a total length of about 12,993 kilometres (8,073 mi) in 2016, which ranks it among the most dense and longest controlled - access systems in the world . Longer similar systems can be found in the United States (77,017 kilometres (47,856 mi)) and in China (123,000 kilometres (76,000 mi)). </P>

What is the average speed on the autobahn