This paper proposes a four-step approach based on technology roadmapping and scenario-based roadmapping. The objective is to evaluate the relevance of new products and technologies and its variation under a range of possible future conditions or scenarios. A case study on rail automation for passenger transport systems is conducted to demonstrate the applicability of the proposed method. Market drivers, new systems, products and technologies are identified in a literature review and then verified and linked by expert judgments. Analyzing the resulting graphical representation of relevance and robustness from the proposed approach leads to a periodization of products and technologies for future development and an evaluation of the most influential market driver. The proposed approach for scenario-based technology roadmapping facilitates robust decision making under future uncertainties.