Autobahns of Austria
Unlike German autobahns, on Austrian autobahns a general speed limit of 130 km/h (81 mph) is set, although as of August 25, 2018, the FPÖ government has been going on a trial for a possible speed limit increase to 140 km/h (87 mph) on the Autobahn 1 freeway. They may only be used by powered vehicles that are designed to achieve at least . While on the motorway voluntary stops, U-turns and backward driving are prohibited.
Speed limit
In 1965, the first known experiments with variable speed limit signs took place on a 30 km stretch of German motorway A8 between Munich and the border city of Salzburg, Austria. Mechanically variable message signs could display speeds of 60, 80 and 100 km/h, "danger zone" or "accident". Personnel monitored traffic using video technology, and manually controlled the signage. Beginning in the 1970s, additional advanced traffic control systems were put into service. Modern motorway control systems can work without human intervention using various types of sensors to measure traffic flow and weather conditions. In 2009, of German motorways were equipped with such systems.