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 the United States by jurisdiction
In Oklahoma, the maximum posted speed limit is 75 miles per hour on turnpikes and 70 mph on all other freeways. Most other rural highways, divided or undivided, have a 65 mph speed limit (although some rural divided highways have a 70 mph limit). The minimum speed limit on almost all Interstate Highways, freeways, and turnpikes is 40 mph, except when the speed limit is 75 mph (found only on turnpikes), in which case the minimum speed is 50 mph. In addition, rural sections of turnpike are supplemented with a sign warning "no tolerance". On May 9, 2016, Governor Fallin signed HB 3167 which removes numerical caps on rural highway speed limits in Oklahoma which took effect in November 2016. Even with this bill the speed limits across the state are not expected to change because of budget issues in doing studies