FrontMatter -- Acknowledgments -- Contents -- Figures and Tables -- Summary -- 1 Introduction and Background -- 2 Management Strategy and Priority Setting -- 3 Engine Systems and Fuels -- 4 Medium- and Heavy-Duty Hybrid Vehicles -- 5 Vehicle Power Demands -- 6 Engine Idle Reduction -- 7 Safety -- 8 SuperTruck Program -- 9 Efficient Operations -- Appendix A: Biographical Sketches of Committee Members -- Appendix B: Presentations and Committee Meetings -- Appendix C: Responses from the 21st Century Truck Partnership to the Findings and Recommendations from the National Research Council Phase 1 Review -- Appendix D: Highlights of Selected Propulsion Material Programs -- Appendix E: Available Models of Medium- to Heavy-Duty Hybrid and Electric Trucks -- Appendix F: Proposed Mechanism for Obtaining Hybrid Vehicle Credits -- Appendix G: History of Heavy-Duty Truck Aerodynamic and Tire Rolling Resistance Coefficients -- Appendix H: Bibliography for Long Combinations Vehicles in Canada, the United States, and Australia -- Appendix I: Acronyms and Abbreviations.