In this chapter, we first address two questions: why are automobiles purchased, and why are automobiles, after being purchased, used to such a large extent? We argue that instrumental and economic factors (including time savings) play important roles. Yet, psychological factors appear to also play a decisive role. Following a brief overview of factors accounting for the unprecedented historical increase in automobile ownership (Section 19.2), determinants of private car use will be analysed in the following section, 19.3. Substantial environmental and societal costs of private car use such as congestion, noise, air pollution, excessive land use crowding out other uses and depletion of material and energy resources are expected future consequences of the worldwide increasing trend in automobile ownership and use (Goodwin, 1996; Greene and Wegener, 1997; van Wee, 2012, 2014). In many urban areas, these consequences are already being felt, leading to various policy measures for reducing or changing private car use being placed high on the political agendas. In Section 19.4, we describe and classify a number of such policy measures. Following this classification, we review in the same section evidence of the policy measures’ effectiveness, public acceptability and political feasibility. Historical Trends in Private Car Ownership and Use The automobile has drastically altered the development of the world like few other human inventions. In the developed countries, and now in developing countries, its versatility strongly contributes to why it is chosen for urban, suburban and rural travel (Jakobsson, 2007). Versatility (in this chapter, referred to as instrumental motives) is, however, not a sufficient explanation. As will be argued, the automobile is also chosen because it is fun to drive and ride, provides privacy and security and signals social status (Gatersleben, 2007, 2014; Stradling, 2002). Even though cars were available at the beginning of the twentieth century, it was only in the years after World War II with the subsequent spread of affluence and the acceleration of automobile mass production that ownership was brought within the reach of a majority of households in the industrialised world.