There are numerous sustainability challenges related to mobility. One of the main challenges is the necessary reduction of greenhouse gas emissions. The transport sector is one of the main emitters. There are also challenges regarding accessibility, health, equity, and justice that need to be considered. The recent COVID-19 pandemic led to a temporary decrease in emissions (mainly from reduced aviation), at the same time as there were worsening aspects such as social exclusion. These and other complex challenges requireurgent, comprehensive change and creative solutions. The urgency for a change adds to the challenge of mobility planning since conventional planning processes are usually slow. Moreover, local planners who plan for transitioning to sustainable mobility need to facilitate participatory processes since mobility planning affects many stakeholders. When engaging with planning practitioners, it was found that there is a lack of tools that can support practitioners when conducting reflective and generative multistakeholder dialogues.

The aim of this research was to develop process-oriented methodological support for multistakeholder dialogues in strategic planning for transitioning to sustainable mobility. A transdisciplinary research approach was used to explore this topic, including the problem space of participatory research modes. Furthermore, a design research approach was used for tool development.

A comprehensive literature review to identify prominent research themes in regional and urban planning for transitioning to sustainable mobility was made. The developments in the field over the past 15 years show a paradigm shift from ‘predict-and-provide’ to participatory visionary approaches, such as backcasting and SymbioCity. However, this has led to new challenges concerning processes that support reflective and generative stakeholder dialogue in a rapidly changing and highly diversified world. These challenges relate to, among other things, an insufficient diversity in multistakeholder processes, a limited availability of stakeholders to participate in such processes and a lack of tools that can aid with an overview of various sustainability goals from policy and planning documents.

Among participatory research approaches, transdisciplinary research and action research were explored. As these research modes have become prominent, it is important to know more about them. It was found that transdisciplinary research could be particularly useful for advisory reflective contexts, whereas action research could be particularly useful for contexts where action is a priority.

The dissertation presents further forms of methodological support that can help structure participatory multistakeholder dialogue-based processes:− a framework for analysing the complexity of co-production settings in relation to epistemic communities, linguistic diversities, and culture;− a rapid scenario planning method to support regional visioning for sustainability transformation; and− the MUSTS tool that connects sustainability goals at multiple levels with stakeholders who have the power and legitimacy to act upon them. To conclude, the methodological process-supporting tools that were investigated and those developed in this research offer a form of “scaffolding”that aids facilitators to organise more efficient and effective participatory processes. These scaffolding tools are rooted in transdisciplinary coproduction of knowledge research and offer promising elements for a toolbox for strategic planning for transitioning to sustainable mobility.