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.
Speed limits in Germany
Posted minimum speeds usually only apply to specific lanes like the common configuration on 6-lane roads with a minimum speed of 110 km/h (68 mph) on the left and 90 km/h (56 mph) on the center lane. Vehicles which cannot sustain speeds of 60 km/h (37 mph) on the flat are not allowed on the Autobahn, however. Because of this, many European self-propelled cranes and other extra-heavy trucks which would be unsafe at much higher speeds, but similarly unsafe or impractical (and certainly obstructive) to drive for long distances on surface streets between job sites and depots, are engineered with maximum design speeds a little over 60 km/h - typically 62 km/h (39 mph) at governed engine speed in top gear.