This paper proposes a methodology, consistent with the Kyoto Protocol's clean development mechanism (CDM), to quantify the greenhouse gas (GHG) emission reduction benefits of transport-efficient development (TED). TED aims to reduce transportation GHGs by changing urban development patterns. The Nanchang Transit-Oriented Development project in China is used to demonstrate the methodology and the possibilities for bringing such projects into the carbon market. The case illustrates the challenges of using the CDM to reduce transportation GHG emissions via TED. The proposed analytical approach, utilizing a control group, encounters difficulties with geographical control, the reliability of the statistical techniques, and challenges to calculating emissions "leakage." These methodological difficulties also affect financial viability because of high monitoring costs and high project risks. Ultimately, the CDM executive board rejected the proposed methodology, suggesting limited possibilities for utilizing today's carbon market to alter developing countries' urban transportation GHG growth trajectories.