Determinants of low-carbon transport mode adoption: systematic review of reviews

Abstract

Urban transport provides access to multiple services, structures and impedes daily life of residents, and translates into wellbeing considerations, sustainability impacts, and GHG emissions. Thus motivated, multiple disciplines, ranging from psychology to urban planning, are invested in understanding the potential for transitioning to low-carbon and sustainable urban transport systems. While each discipline has carved out a growing body of knowledge, a consistent cross-disciplinary understanding of psychological, sociological, and urban form determinants of urban mobility choices is, perhaps surprisingly so, still lacking. Here, we systematically review the reviews of several strands of literature and lay out the evidence for individual, social, and infrastructure level factors pertinent to urban mode choice. Synthesizing the results from 75 review papers, we find that all three dimensions (individual, social, and infrastructure) unambiguously interfere with mode choice. Individuals are most motivated to shift modes, if they are well informed, if personal norms match low-carbon mode use, and, most importantly, if they perceive to have personal control over decisions. Perceptions about common travel behaviour (descriptive social norms), especially if supported by perceived normative beliefs of others (injunctive norms), are highly influential to support mode shift. However, the overall margin of shift as induced by individual and social settings remains limited. Instead, the infrastructure factors explain large differences in mode choice. New shared mobility modes, and teleworking and shopping, add a long tail to modes chosen, but are no game changer. We conclude that a transition to low-carbon mobility requires low-carbon infrastructure, which leverages enthusiastic individuals’ concerns and empowers them for mode change, and that address safety concerns prevalent especially in cities of the Global South. The mode shift to low-carbon option can then be sustained and enhanced by social influence in the form of collective social norms.