Veenma, KlaasLeendertse, WimArts, Jos2023-04-282023-04-282022978-9916-4-1319-7https://hdl.handle.net/20.500.14235/172Infrastructure planning is increasingly confronted with a dynamic environment and an engaged society. This necessitates decision makers to interact with their environment, resulting in the adoption of adaptive and participative planning approaches such as combined infrastructure and (organic) area development (De Roo et al., 2020). Giving room to stakeholders and to unforeseen developments implies incorporating uncertainty in planning and decision making and increases the complexity of planning. In current infrastructure planning, decision makers seem to struggle to find a balance between giving room to uncertainties on the one hand, and keeping the decision-making process manageable on the other hand. This often results in attempts to reduce uncertainties, in 'certainification' (Van Asselt et al., 2007; Klijn & Koppenjan, 2016). This focus on certainification prevents adaptive and participative approaches in planning from reaching full maturity (Hajer et al., 2010; Albrechts, 2012). This paper is based on a recent studyeninfrastructure planningCertainficationdecision-makinguncertaintyurban policiesplanning policiesRoom for Uncertainty in Infrastructure Planning How Continuous Certainification by Decision Makers Results in More UncertaintyArticle191-198