The development of sustainable urban mobility systems requires collaboration across various stakeholders, including transport and spatial planning, public administration, companies, and research institutions. Open Innovation (OI) environments, such as Urban Mobility Labs (UML), have emerged as platforms for fostering these collaborations and facilitating innovation in mobility. In Austria, the government has funded UML initiatives since 2015, with six labs currently in operation. This paper analyses the organizational structures of these UMLs, using empirical data from a qualitative study conducted during the second phase of the initiative (2017-2021). Key findings indicate that the size and composition of the UML consortia significantly influence the formalization and operational efficiency of these labs. Smaller consortia are more agile but face resource constraints, while larger consortia benefit from greater expertise but are burdened by higher coordination costs. Successful UMLs balance these dynamics through lean organisational structures, clear role distribution, and efficient processes. The analysis also explores the legal frameworks for UMLs, recommending hybrid models that integrate the strengths of both independent entities and existing institutions. These insights contribute to the longterm sustainability of UMLs by proposing organisational models that support efficient governance and business model development.
