While the number of projects under the Clean Development Mechanism (CDM) is expanding rapidly, there currently are relatively few transport projects in the global CDM portfolio. This article examines existing CDM transport projects and explores whether sectoral approaches to the CDM may provide a better framework for transport than the current project-based CDM. We ask: Would a sectoral approach to the CDM promote the structural change and integrated policymaking needed to achieve sustainable transport policy, making it hence more desirable than the framework of the current project-based CDM? We conclude that it is possible to design sectoral transport activities within clear project boundaries that fit into a framework of a programmatic or policy-based CDM. Although we are able to ascertain that transport policy research yields several modelling tools to address the methodological requirements of the CDM, it becomes apparent that sectoral approaches will accentuate transport projects' problems regarding high complexity and related uncertainties. The CDM may need new rules to manage these risks. Nonetheless, sectoral approaches allow the scaling up of activities to a level that affects long-term structural change.