Lately, there has been a tendency in academia to call for more interdisciplinary research on sustainable mobility. However, there is a lack of empirical research on practiced interdisciplinarity. This paper seeks to address this by exploring the practices of an intended interdisciplinary doctoral research group. Specifically, it presents the study of a collaborative autoethnography using individual vignettes and qualitative data analysis. The results classify the identified interdisciplinary practices into three main categories: Interactions, productive processes, and negotiation processes, where interactions serve as a carrier for negotiation and productive processes. This also uncovers advantages and challenges associated with these interactions. Furthermore, the analysis reveals intersubjectivity as an important component of the infrastructure of interdisciplinarity involved in both processes. Finally, we call for a reevaluation of the hierarchical thinking about the different levels of interdisciplinarity, going from disciplinary to multidisciplinary to interdisciplinary to transdisciplinary research. We conclude that for interdisciplinarity to happen in practice, it requires having a combination of various disciplines, ontologies, and a common “wicked” problem to solve. We also find that developing an interdisciplinary research environment requires researchers to embark on a shared journey of reaching a higher level of intersubjectivity through continuous interactions and discussions, while also negotiating conflicts.