SUMP was carried out with high participation of internal and external stakeholders over a two-year period. In the workshops, focus group meetings, surveys and one-on-one interviews conducted within the scope of the study, particular attention was paid to ensure the participation of groups with low representation. Since the beginning of the study, 220 stakeholders have been involved in the project through 25 online workshops and other methods. In the last 6-month period, online workshops have been held in April and September 2021 160 stakeholders were invited, more than 80 of whom are outside of IMM, whose participation is continuous and thus well-versed in the process. In the first workshop at this stage, project proposals for policy packages determined by participatory processes within the scope of SUMP were received from the participants, and in the second workshop, comments on 26 projects grouped under themes and defined as main projects by the technical team and the priorities of these projects in terms of Istanbul’s transportation system were discussed.