Quote:On 12 March 1938 Hitler invaded Austria, and the next day proclaimed Anschluss, the absorption of Austria into Germany. He ordered that the traffic should change from the left to the right side of the road, overnight
Well, that is not a correct description of the events.
Before WWI there was a "mixed" system i Austria. In 1914 a "einheitliche Linksfahrordnung" (uniform left-hand driving) was introduced in all territories of the Austrian-Hungarian Monarchy.
Already in 1919 some parts of the remaining Austria reverted to right-hand driving. It was also decided the a conversion should take place in the whole of the country before the 1 of December 1932 (Strassenpolizei-Grundsatzgesetz 1929). This law was, however, not implemented.
Already before "Anschluss" right-hand driving was introduced in Tyrol and Carinthia.
In the rest of the country the change took place in two steps: 1 of July 1938 and 19th of September 1938. The last date had to do with the vast tramway network of Vienna, which had to be rebuilt.