 Ideas to build up a limited-access road network with grade separated interchanges had been developed already in the 1920s, including a "Nibelungen" highway along the Donau (Danube) river from Passau to Wien (Vienna) and further on towards Budapest.Those plans however had never been carried out due to the lasting economic crisis that hit the country after the dissolution of Austria-Hungary in 1918, exacerbated by the Great Depression.The first autobahn on Austrian territory was the West Autobahn from Salzburg to Wien.