Abstract
Accelerating sustainability transitions is increasingly treated as a societal imperative, yet acceleration can also intensify “dark side” dynamics such as obstructive lock-ins, injustices, and backlash. While transition scholarship has begun to theorise these effects at contextual levels, we still lack systematic understanding of how they are enacted through projects, the vector of changes that contribute to sustainability transitions. This paper addresses that gap through a systematic literature review and thematic analysis of 78 peer-reviewed empirical case studies. Aiming to address “What, when, and How dark sides of acceleration manifest in transition projects?”. Findings identify three recurring patterns, obstructive lock-ins (technology generation lock-in and partial system change), transition injustice (procedural, recognitional, and distributional), and backlash (lock-in and injustice backlash), which are often coexist and mutually reinforcing. The review conceptualises projects as key loaction where acceleration’s benefits and harms are materially produced, and it identifies project-level intervention points to mitigate dark sides.