EXPANDING METROPOLITAN HIGHWAYS -- Copyright -- Preface -- Contents -- Executive Summary -- REGULATORY CONTEXT -- ANALYTIC REQUIREMENTS -- FINDINGS -- CONCLUDING OBSERVATIONS -- REFERENCES -- ABBREVIATIONS -- 1 Introduction -- REGULATORY CONTEXT -- Clean Air Legislation and Regulatory Requirements -- Historical Trends -- Requirements of the 1990 CAAA -- Conformity Requirements -- ISTEA -- Energy Regulation -- STUDY FOCUS -- DEFINITION OF TERMS -- OVERVIEW OF IMPACTS -- ASSESSMENT OF IMPACTS -- ORGANIZATION OF REPORT -- NOTES -- REFERENCES -- ABBREVIATIONS -- 2 Contribution of Motor Vehicle Transportation to Air Pollution and Energy Consumption -- TRANSPORTATION AND AIR QUALITY -- Transportation-Related Pollutants -- Formation of Motor Vehicle Emissions -- Major Pollutants by Type -- Pollutants by Vehicle and Fuel Type -- Factors Affecting In-Use Emission Levels -- Travel-Related Factors -- Trips and Vehicle Use -- Speed, Acceleration, and Load -- Driver Behavior -- Highway-Related Factors -- Vehicle-Related and Other Factors -- Translating Emissions into Air Quality -- TRANSPORTATION AND ENERGY CONSUMPTION -- Energy and the Environment -- Factors Affecting In-Use Fuel Economy -- Travel-Related Factors -- Driver Behavior -- Highway-Related Factors -- Vehicle-Related and Other Factors -- MODELING AIR QUALITY AND ENERGY IMPACTS -- Introduction to Modeling Requirements and Approaches -- Land Use and Travel Demand Models -- Land Use Models -- Travel Demand Models -- Traffic Simulation Models -- Emission and Atmospheric Dispersion Models -- Emission Models -- Atmospheric Dispersion Models -- Energy Models -- Limitations of Current Modeling Practice -- SUMMARY -- NOTES -- REFERENCES -- ABBREVIATIONS -- 3 Traffic Flow Characteristics -- OVERVIEW OF EXPECTED IMPACTS -- REVIEW OF EFFECTS ON EMISSIONS -- Effects of Changes in Traffic Flow Patterns.

Drive Cycles and Average Speed -- Estimates from Current Emission Models -- Certainty of Emission Estimates from Current Models -- Linking Emissions Estimates with Data on Traffic Flow Characteristics -- Status of Current Research and Modeling Efforts -- Research on In-Use Vehicle Emissions and Emission Modeling Improvements -- Research on Emissions Effects of Sharp Accelerations and Fuel Enrichment -- Research on Emissions Effects of High-Speed Driving -- Implications of Research for Emissions Modeling -- Traffic Simulation Modeling Improvements -- Effects on Travel Volumes -- Network Effects -- SUMMARY ASSESSMENT OF EFFECTS ON EMISSIONS AND AIR QUALITY -- Net Effects on Emissions -- Effects on Regional Air Quality -- REVIEW OF EFFECTS ON ENERGY USE -- Estimates from Current Models -- Certainty of Fuel Economy Estimates -- Net Effects on Energy Use -- SUMMARY ASSESSMENT AND RECOMMENDATIONS FOR IMPROVING THE KNOWLEDGE BASE -- NOTES -- REFERENCES -- ABBREVIATIONS -- 4 Travel Demand -- DETERMINANTS OF METROPOLITAN TRAVEL DEMAND AND RECENT TRAVEL TRENDS IN THE UNITED STATES -- OVERVIEW OF EXPECTED IMPACTS AND DEFINITION OF TERMS -- Description of Effects -- Definition of Induced Travel -- THEORETICAL UNDERSTANDING OF TRAVEL CHOICES AND IMPACTS -- REVIEW OF EVIDENCE FROM STUDIES -- Facility-Specific Studies -- Methodological Problems -- Study Results -- Areawide Studies -- Methodological Problems -- Study Results -- Travel Time Elasticities -- Methodological Problems -- Study Results -- Summary of Findings from Studies -- REVIEW OF IMPACTS FROM TRAVEL DEMAND MODELS -- SUMMARY ASSESSMENT OF THE STATE OF KNOWLEDGE -- REVIEW OF IMPACTS ON TRUCK TRAVEL -- Effects on Truck Traffic -- Modeling Truck Travel -- RECOMMENDATIONS FOR IMPROVING THE KNOWLEDGE BASE -- NOTES -- REFERENCES -- ABBREVIATIONS -- 5 Land Use and Urban Form -- BACKGROUND.

Arguments Against Capacity Additions -- Research Questions -- Context of Transportation-Land Use Relationship -- Net Growth and Redistributed Growth -- Demographic Influences on Growth -- THEORY LINKING TRANSPORTATION AND LAND USE -- EMPIRICAL EVIDENCE -- Cross-National Comparisons -- Studies of Housing and Residential Location -- RESULTS FROM MODELS -- Optimization Models -- Spatial Interaction Models -- IMPLICATIONS OF CHANGES IN POPULATION DENSITY FOR TRAVEL AND EMISSIONS -- SUMMARY -- RECOMMENDATIONS FOR IMPROVING THE KNOWLEDGE BASE -- Behavioral Research -- Modeling -- NOTES -- REFERENCES -- ABBREVIATIONS -- 6 Findings and Conclusions -- OVERVIEW -- CROSSCUTTING ISSUES -- FINDINGS FOR INDIVIDUAL IMPACT AREAS -- Initial Impacts on Traffic Flow Characteristics -- Impacts on Travel Demand -- Impacts on Land Use and Urban Form -- SUMMARY ASSESSMENT OF NET EFFECTS -- RECOMMENDATIONS FOR RESEARCH, MODELING IMPROVEMENTS, AND DATA COLLECTION -- Emissions Modeling -- Travel Demand and Land Use Forecasting Models -- CONCLUDING OBSERVATIONS -- NOTES -- REFERENCES -- ABBREVIATIONS -- Appendix A Emission and Energy Characteristics of Heavy-Duty Diesel-Powered Trucks and Buses -- FLEET CHARACTERIZATION -- Truck Classification -- Engine Types -- Diesel Truck Population, Use, and Scrappage -- HDDV EMISSION CONTROL PROGRAMS -- Introduction -- HDDV Emissions Standards -- Federal HDD Emission Standards -- California HDD Emissions Standards -- Diesel Fuel Specifications -- Clean Fuel-Low Emission Heavy-Duty Vehicles -- HDDV Inspection and Maintenance Programs -- HDDV EMISSIONS AND SPEED CORRECTION FACTORS -- Overview -- Comparison Between the Steady State and Transient Test Emissions -- Vehicle Versus Engine Emissions -- HDDV Emission Factors -- Speed Correction Factors -- HEAVY-DUTY TRUCK FUEL ECONOMY -- Average Fuel Economy -- Fuel Economy Dependence on Speed.

Emission Conversion Factor -- SUMMARY -- NOTES -- REFERENCES -- ABBREVIATIONS -- Appendix B Review of Empirical Studies of Induced Traffic -- FACILITY-SPECIFIC STUDIES -- AREAWIDE STUDIES -- TRAVEL TIME ELASTICITIES -- NOTE -- REFERENCES -- ABBREVIATION -- Appendix C Impact of Changes in Highway Capacity on Truck Travel -- GENERAL IMPACT OF CHANGES IN HIGHWAY CAPACITY -- Extensiveness of Existing Highway Network -- Limited Exposure of Trucks to Congestion -- Low Freight Transportation Costs -- SPECIFIC RESPONSES TO CHANGES IN HIGHWAY CAPACITY -- Reallocation of Truck Travel -- Changes in Travel Hour -- Changes in Route -- Changes in Destination -- Induced Travel -- Changes in the Number of Trips -- Changes in Trip Length -- Changes in Mode -- TRENDS -- TRUCKS, CONGESTION, AND SAFETY -- MODELING TRUCK TRAVEL -- CONCLUSIONS AND RECOMMENDATIONS -- NOTES -- REFERENCES -- ABBREVIATIONS -- Appendix D Review of Studies of Transportation Investments and Land Use -- MAJOR HIGHWAY INVESTMENTS -- Beltways -- Major Capacity Expansions -- Development Patterns -- Development Decisions -- MAJOR RAIL INVESTMENTS -- U.S. Rail Transit Impacts -- Canadian Rail Transit Impacts -- NOTE -- REFERENCES -- ABBREVIATION -- Appendix E Minority Statement of Michael A. Replogle -- KEY FINDINGS -- INDUCED TRAFFIC EFFECTS: FINDINGS FROM A MAJOR UNITED KINGDOM STUDY -- DETERMINANTS OF TRAVEL DEMAND -- Effects of Subsidies -- Effects of Added Highway Capacity on Freight Travel Demand -- Effects of Added Highway Capacity in Built-Up Areas -- Consideration of Alternatives to Highway Capacity Expansion -- London -- Copenhagen -- EFFECT OF REDUCED HIGHWAY SPEED AND CAPACITY -- Reducing Road Speed and Capacity with Traffic Calming -- Reducing Road Capacity with Traffic Cells for Environmental Benefit -- EFFECT OF HIGHWAY CAPACITY ADDITIONS ON METROPOLITAN FORM.

DATA COLLECTION, MODEL DEVELOPMENT, AND RESEARCH NEEDS -- THE BUILD-NO-BUILD TEST AND REGULATORY BACKLASH -- New Scientific Uncertainty or Just a New Backlash? -- Real Problems with Build-No-Build -- Highlight Near-Term Model Reform Needs -- REFERENCES -- ABBREVIATIONS -- Study Committee Biographical Information.