An Assessment of Advanced Transportation Research Opportunities

Fundamental research can play a role in reducing greenhouse gas emissions associated with growing global transportation energy use by enabling technologies that either significantly reduce the energy requirement of transportation or decouple vehicle energy use and emissions. Current research toward these ends is summarized, not including research areas outlined in other GCEP assessment reports with relevance to transportation such as hydrogen, combustion, and biomass. Reducing the energy requirement for transportation may be accomplished by reducing vehicle mass, smoothing the operational speed profile, and reducing viscous and contact friction. Specific technical challenges in these areas include the low-cost production of high-strength, low-weight materials and the technical foundation to enable automated vehicles. Fuel chains with low net greenhouse gas emissions include portable storage of low-carbon electricity and carbon-based fuels synthesized from low-carbon energy. Significant technical challenges in this area include developing batteries with high energy density and stability and developing classes of low-cost catalysts capable of efficiently converting low-carbon energy into and out of forms amenable for portable storage.