Transformative Reduction of Transportation Greenhouse Gas Emissions: Opportunities for Change in Technologies and Systems

Reaching deep reductions in greenhouse gas emissions from the U.S. transportation sector will require diverse system and technology development strategies targeting energy intensity, carbon intensity, and demand for transportation services. Technological, economic, demographic, and social trends shape the likelihood of reaching a reduction threshold consistent with what climate scientists report is needed by 2050. This report summarizes work for the U.S. Department of Transportation's Clean Transportation Sector Initiative and builds upon the U.S. Department of Energy's Transportation Energy Futures review of opportunities for reductions in petroleum use and GHG emissions. It contributes to the literature by summarizing the potential of emerging emissions-reducing technologies and strategies, including vehicle electrification through plug-in or fuel cell vehicles, connected and automated vehicles, biofuel pathways, vehicle efficiency, and transportation demand reduction. The potential of these and other emerging technologies and strategies was explored at a Clean Transportation Sector Initiative workshop. Key findings from this workshop are incorporated into this report, and the event details are summarized in Appendix C.