The Autobahn (IPA: [ˈaʊtoˌbaːn] ; German pl. Autobahnen, pronounced [ˈaʊtoˌbaːnən] ) is the federal controlled-access highway system in Germany. The official term is Bundesautobahn (abbreviated BAB), which translates as 'federal motorway'. The literal meaning of the word Bundesautobahn is 'Federal Auto(mobile) Track'.
Much of the system has no speed limit for some classes of vehicles. However, limits are posted and enforced in areas that are urbanised, substandard, prone to collisions, or under construction. On speed-unrestricted stretches, an advisory speed limit (Richtgeschwindigkeit) of 130 kilometres per hour (81 mph) applies. While driving faster is not illegal in the absence of a speed limit, it can cause an increased liability in the case of a collision (which mandatory auto insurance has to cover); courts have ruled that an "ideal driver" who is exempt from absolute liability for "inevitable" tort under the law would not exceed the advisory speed limit.