Key Uncertainties in Mega Projects – Lessons learned from 34 projects

Megaprojects are inherently complex and uncertain, yet traditional risk management approaches often fall short in capturing the full range of uncertainties that leaders face throughout the project lifecycle. This study explores how megaproject leaders experience uncertainty across different project phases, using Rolstadås and Johansen’s framework of operational, strategic, and contextual uncertainty. Drawing on qualitative data from 34 megaprojects (28 infrastructure and 6 building projects), based on semi-structured interviews, project documentation, and field notes, we identify key sources of uncertainty and examine their implications for project leadership. Our findings reveal that all three categories of uncertainty are persistent and dynamic, with operational uncertainties often rooted in technical complexity and organizational fluidity, strategic uncertainties tied to labor, funding, and ownership engagement, and contextual uncertainties arising from political influence, regulatory change, and societal expectations. These uncertainties tend to intensify in later project phases, placing high adaptive demands on leadership and governance structures. We argue for a shift from static risk registers to more flexible, participatory approaches that can address the evolving interplay of internal and external uncertainty drivers. This research offers both theoretical and practical insights into managing uncertainty in complex, high-stakes project environments.