Viktoria Isabell Fatima Allert

• Engaging citizens as political agents of change is essential for achieving an environmentally sustainable and socially just mobility transition. However, the current car-centric mobility system, with its economic and political entrenchments, resists change. This dissertation contributes to a better understanding of how individuals can drive systemic changes in mobility through active citizenship. It does so by examining exemplary behaviors individuals can adopt to challenge the car-centric transport system and explores their behavioral antecedents. First, I review conceptualizations of agency and pro-environmental social change within transitions literature and environmental psychology respectively. In Chapter 2, I explore how individuals can foster social norm shifts by changing their mode choice, thereby renegotiating structures of normality in transport behavior. Chapter 3 investigates how the social identification with transport user groups impacts the willingness to actively support contested transport policies, such as the redistribution of street space. In Chapter 4, I explore the interplay between social identity processes that motivate collective action against car-dependent structures and the systemic characteristics of the transport regime. Moving on to Chapter 5, I explore the challenges and potential of citizen assemblies in driving local changes in mobility by focusing on discourses in a deliberative envisioning process. Finally, Chapter 6 discusses theoretical and practical implications that can be derived from this thesis, highlights avenues for future research and acknowledges the limitations of this thesis. In this dissertation I focused on integrating social psychological knowledge, particularly Social Identity Theory, with sociology and the Multi-Level-Perspective from Transition Studies to deepen our understanding of individual agency within the mobility transition. The findings indicate how through active citizenship individuals can partake in shaping the mobility transition – for example through supporting policies, engaging in activism or partaking in formal participation processes. However, obstacles such as limited problem recognition, discourses that delay mitigation action or feelings of powerlessness in regard to industry actors can hinder engagement, especially if the behavior is costly. Conversely, evoking positive emotions towards a sustainable mobility system as well as highlighting co-benefits of a mobility transition as common goals seems to be effective in motivating action. These results suggest that there is merit in involving citizens as political actors throughout different stages of the mobility transition and emphasize the need for future interdisciplinary research to further investigate underlying motivational factors of engagement.