<P> In Germany, the Autobahn - Richtgeschwindigkeits - Verordnung (Directive on Reference Speed on Motorways), introduced in 1974, recommends a speed of no more than 130 km / h (81 mph) for autobahns and similar roads, whose lanes are separated by a median or which have at least two lanes per direction, provided there are no traffic signs posting a lower speed limit . </P> <P> Until 31 August 2009, a different reference speed could be posted by the traffic signs number 380 and 381, according to § 42 of the German traffic code (Straßenverkehrsordnung, StVO), as seen above . As these traffic signs were only rarely used, they meanwhile have been abolished . </P> <P> The signage for advisory speed limits is not defined by the Vienna Convention on Road Signs and Signals, and is therefore not standardised internationally . The United States uses a small yellow sign under the main warning sign, as well as a standalone variation on the standard speed limit sign, with a yellow background instead of a white one, the words "speed limit" omitted and an additional panel stating the type of hazard ahead . Though they list speeds, the U.S. advisory speed signs are classified as warning signs, not regulatory signs, as primary speed signs are . Australia uses a similar design as the U.S. in spite of regulatory speed limit signs being quite different . Germany used a square sign with a blue background and white lettering, similar to the minimum speed limit sign, and New Zealand uses a yellow background with black lettering (similar to the Australian design without the "km / h" lettering). The United Kingdom currently uses an oblong white rectangle with black lettering stating "Max Speed". </P> <Ul> <Li> <P> Most of Europe </P> </Li> <Li> <P> Australia </P> </Li> <Li> <P> Australia (motorway exits) </P> </Li> <Li> <P> Australia (with diagram of motorway exit shape) </P> </Li> <Li> <P> Victoria, Australia </P> </Li> <Li> <P> Western Australia, Australia (traffic - calming bumps, known as speed bumps) </P> </Li> <Li> <P> Canada </P> </Li> <Li> <P> Canada (Ontario) (highway ramps and exits) </P> </Li> <Li> <P> Denmark </P> </Li> <Li> <P> Finland </P> </Li> <Li> <P> Japan </P> </Li> <Li> <P> Netherlands </P> </Li> <Li> <P> New Zealand </P> </Li> <Li> <P> New Zealand (motorway exits) </P> </Li> <Li> <P> New Zealand (dangerous curve) </P> </Li> <Li> <P> New Zealand (extremely dangerous curve) </P> </Li> <Li> <P> New Zealand (warning of danger of truck roll - over) </P> </Li> <Li> <P> Norway </P> </Li> <Li> <P> Philippines </P> </Li> <Li> <P> South Korea </P> </Li> <Li> <P> Sweden </P> </Li> <Li> <P> United Kingdom (imperial) </P> </Li> <Li> <P> United Kingdom (roadworks, imperial) </P> </Li> <Li> <P> United States (customary) </P> </Li> <Li> <P> United States (metric) </P> </Li> <Li> <P> United States (highway exits) </P> </Li> <Li> <P> United States (highway ramps) </P> </Li> <Li> <P> United States (highway curves) </P> </Li> <Li> <P> United States (warning of danger of truck roll - over) </P> </Li> <Li> <P> United States (integrated into curve warning sign) </P> </Li> </Ul>

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