-xxi- ACKNOWLEDGMENTS Many people made valuable contributions to this report. Technical reviews of the draft report were provided by Frank Camm at RAND, Howard Gruenspecht at Resources for the Future, and Tim Lipman at the Renewable and Appropriate Energy Lab, UC Berkeley. We thank them for their detailed, insightful comments, which led to the report being improved considerably. Steve Albu, Paul Hughes, Mike McCarthy, and Chuck Shulock at the California Air Resources Board (CARB) provided very thoughtful feedback on the draft report. Cynthia Marvin and Andrew Panson at CARB and Laki Tisopulos at the South Coast Air Quality Management District provided documentation and interpretation of recent amendments to the State Implementation Plan for Ozone. Alec Brooks and Tom Gage at AC Propulsion, David Friedman at Natural Resources Defense Council, Karl-Heinz Hauer at Xcellvision (in Wolfsburg, Germany), and Ben Knight at Honda helped us find and interpret information on battery and fuelcell technologies. Within RAND, Jim Bartis helped us develop estimates of electricity and hydrogen costs and provided useful comments on an interim draft. Paulette Middleton explored issues that underlie the vehicle emissions estimates, and Mark Bernstein helped frame the issues. Steve Rattien, director of RAND’s Science and Technology Unit, provided helpful feedback during the project. Debra Knopman managed the review process and made valuable suggestions for improving the report. The document was edited by Jeri O’Donnell and corrected and formatted by Pat Williams and Joanna Nelsen. We thank them all for their contributions.