This 2008 report from Oak Ridge National Laboratory summarizes the results of analyses funded by the U.S. Department of Energy to evaluate alternative scenarios for deployment of hydrogen fuel cell vehicles and fueling infrastructure in response to the requirements of Section 811 of the Energy Policy Act of 2005 and the recommendations of the National Academy of Sciences Report, The Hydrogen Economy, published in 2004. Achieving a successful transition to hydrogen-powered vehicles in the U.S. automotive market will require strong and sustained commitment by hydrogen producers, vehicle manufacturers, transporters and retailers, consumers, and governments. The interaction of these agents in the marketplace will determine the real costs and benefits of early market transformation policies, and ultimately the success of the transition itself.