Regional governments and regional intergovernmental organizations play an increasingly important role in land use and transportation planning in many countries. In the U.S., regional organizations such as metropolitan planning organizations provide regional forums and institutions to coordinate actions of local government necessary to overcome collective action problems that result from the fragmentation of local authority. Their regional scope allows them to directly address collaboration problems or broker collaborative arrangements among local governments within their boundaries. Nevertheless, the scale of regional problems often extends beyond the boundaries of these regional entities. Thus, collaboration across regional governance organizations is necessary to address problems that have multi-regional impacts, such as large transportation projects. Extant research generally measures regional collaboration based on counts of collaboration actions undertaken, but this does not account for the fact that some are symbolic, while others require resources and commitment. Drawing insights from the institutional collective action framework, we advance an explanation for how regional organizations overcome collaboration risks to participate in collaborative solutions to regional and multi-regional problems. The analysis employs a unique national survey of metropolitan planning organizations (MPOs) and adds a novel application of item response theory (IRT) to capture differences in risk or difficulty among collaborative actions. The IRT results offer support for our ICA-based explanation of collaboration commitments. The implications of the findings for theory development and empirical study of RIGOs are discussed in conclusion.