Powerful research is about how we turn knowledge into action, both during and after a study. This chapter reviews the findings across the case studies, suggesting a growing emphasis on a critical realism approach to knowledge production may emphasize qualitative and mixed methods in transport to address systems of power for social and environmental progress. However, it provides counterpoints that knowledge of wicked problems may never be fully uncovered, and that mixed methods may over-complicate and needlessly delay finding suitable answers in some contexts. This chapter provides practical tools to assess how transport research is used in policy making, centered on how it is communicated. The concluding section points to the progress and problems that remain for researchers and scholars seeking transport truths.

A slow, steady rise for critical realism?

Traditional transport research has predominantly gravitated towards either positivist frameworks, which emphasize empirical observation and quantifiable variables, or interpretive frameworks, which prioritize subjective experience and contextual understanding. In this duality, critical realist approaches have been comparatively underutilized. Critical realism, a philosophy that combines elements of positivism and interpretivism, posits that while an objective reality exists, our understanding of it is always mediated by social, cultural, and linguistic factors. In other words, it seeks to understand not just the ‘what’ but also the ‘why’—the underlying mechanisms and structures that give rise to observable phenomena.