During the economic crisis of the 1920s, World War II and the post-war period, racing operations had to be interrupted time and again. However, the Avus served not only as a race track, but also as a test track for road construction. A steep curve was built at the northern loop in 1937, which was later dismantled after several accidents. Other elements of today's road construction were also tested there. Since the Avus was urgently needed as a connecting route in reunified Berlin, it became increasingly difficult to hold races in the 1990s. The last race took place in April 1998. Since its big closing party on May 01, 1999, the Avus has only been used as a highway.