Zero-car households - constraint or lifestyle choice? A systematic literature review of the factors affecting non-car ownership

At a time when global efforts to reduce CO2 and other emissions from transport are gaining momentum, this paper provides a novel, interdisciplinary systematic review of 106 peer-reviewed studies researching zero-car households. The review consolidates international knowledge on the individual and systemic factors influencing zero-car households at the micro (individuals or households), meso (groups or communities), and macro (governmental) scale. In addition to insights into effective policy interventions to reduce dependence on private car ownership, we offer two novel contributions to transport research. Firstly, we find that 75% of studies are uninformed by any social science theories which limits the actionable and generalisable insights that can be made on car reduction. Secondly, this is the first systematic review to draw a distinction between households which are zero-car by constraint (car-less) versus choice (car-free). This differentiation offers important insights into the contrasting needs and priorities of the two groups. A consistent finding across contexts is that low-income, child-free adults are closely associated with zero-car households. There is no evidence that zero-car householders have pro-environmental values but, in some countries, affluent and well-educated city-dwellers are choosing to live car-free. However, there remain practical and emotional barriers to becoming a zero-car household by choice. Effective policy interventions to encourage zero-car households are found to include residential parking controls and car clubs. The review deepens current understanding of car ownership trajectories and public acceptability of car use and ownership policies. It informs both academics and policymakers in addressing knowledge gaps critical for advancing sustainable urban mobility.