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
Urban districts by default are posted at . Outside of the municipal limits, two-lane state and federal highways have a speed limit of unless otherwise posted, and 2 lane county roads have a speed limit of unless otherwise posted. In June 2015, the Arkansas Highway Commission authorized the Arkansas Highway and Transportation Department (AHTD) to raise the speed limit on undivided 4 and 5 lane roads from while divided 4 lane roads are set to go from , these changes affect of Arkansas highways. Furthermore, AHTD has established freeway default speed limits. Along rural freeways the limit is while suburban freeways are posted at . School zone speed limits apply only when children are present, or when a lighted beacon is on if one is provided and such speed limits are set at unless otherwise posted. It is fairly common however that schools serving only higher grade levels will not have a school speed limit in rural areas or where such school sits more than off of the highway or street.