Abstract
A National Research Council report estimates the maximum practicable number of hydrogen fuel cell vehicles (HFCVs) that could be deployed in the United States by 2020 and beyond, together with the investments, time, and government actions needed for the transition. HFCVs can contribute to large and sustained reductions in U.S. oil consumption and carbon dioxide emissions, according to the report, but several decades will be needed to realize the potential long-term benefits.