This article uses the framework proposed by Rouwette et al. (2002) that has been tested by Stave (2005) to report group model building intervention of a project to develop vehicle emission reduction strategy in Jakarta, Indonesia. The project is among the first attempt that was conducted in the developing country to solve the public issue. Many rapidly developing countries exhibit a faster vehicle emission grows over time compare to those of developed world at comparable income per capita (Marcotulio et al., 2005:125). Consequently, the need to solve the problem under the economic restriction is pressing. The case supports the findings of Rouwette et al. (2002) regarding a strong connection between group model building and group learning about the problem. The group has not reached a consensus, as the participants who attended the final meeting were not broad enough. Nevertheless, the findings demonstrate a potential of the group model building intervention to build a consensus among stakeholders. The approach in setting up the workgroup needs a modification to enhance the stakeholders’ participation throughout the meetings.