Speed limits in Germany
In 1973, in the wake of the 1973 oil crisis, a federal speed limit of 100 km/h (62 mph) on Autobahns was imposed to help conserve fuel for fear of impending future shortages (not for environmental or safety reasons). The measure only lasted from December 1973 to March 1974; while the administration and the Bundestag were in favor of keeping the speed limit, the Bundesrat pushed to repeal the law. As a compromise, a "recommended speed" was introduced on Autobahns and "highways outside of built-up areas with a center divide or without a center divide and a continuous lane for overtaking in both directions". This law is basically still in effect today. Unrestricted non-Autobahn highways, however, have since become virtually non-existent or replaced by "Schnellstraßen", Autobahn-like expressways typically limited to 120 or 130 km/h and normally only covering a few kilometers.
Bundesautobahn 24
On that road, there is a 150 km (93 mi) long section that has no speed limit at all (only a recommended speed of 130 km/h), which means that about 65% of that Autobahn can be driven at very high speed.
Planning for the autobahn began as far back as the 1930s; before World War II numerous bridges and sections of roadside shoulder were built between Hamburg and Berlin. The German divide, however, put a hold on further work and it was not until 1978 that construction was resumed, carried out by a GDR work force and paid for by West Germany. In 1982 the A 24 could finally be opened. Most pre-war bridges could not be used, however, and were replaced by new structures.