Long-term investments challenge decision makers to look into the far future. Existing future studies often build upon a rational idea of decision making that does not help to explain why decision makers anticipate the future. In addition, existing studies do not provide a clear definition of what is considered as forward looking. This article proposes a framework that can be used to evaluate and explain for what reasons and based on what criteria decision makers take forward-looking investment decisions. We apply this framework to a specific decision-making case about a Dutch sea lock, making use of interviews (n = 16) and a content analysis of primary documents (n = 430). We find that not all investment decisions are necessarily forward looking. Secondly, we conclude from our case that decisions became forward looking because administrators used scenarios, visions, and flexible solutions to build support, avoid political risks and comply to formal rules. Scenario developers and urban planners could therefore involve administrators in early stages of the decision-making process to increase their awareness of the future towards which they are steering and provide them with alternative future paths. Furthermore, they could identify and use relevant institutional rules with forward-looking features to stimulate forward-looking decisions.