Task: Question Generation
Input (English): Melbourne is typical of Australian capital cities in that after the turn of the 20th century, it expanded with the underlying notion of a 'quarter acre home and garden' for every family, often referred to locally as the Australian Dream. This, coupled with the popularity of the private automobile after 1945, led to the auto-centric urban structure now present today in the middle and outer suburbs. Much of metropolitan Melbourne is accordingly characterised by low density sprawl, whilst its inner city areas feature predominantly medium-density, transit-oriented urban forms. The city centre, Docklands, St. Kilda Road and Southbank areas feature high-density forms.
Output (English): Which year marked the start of the private automobile's popularity increase?