___________________________________________________ Study & Report to Congress: Applicability of Maximum Axle Weight Limitations to Over-the- Road and Public Transit Buses Pursuant to Senate Report No. 107-38 December 2003 Acknowledgements This project benefited from the information, insights and comments provided by the following people at the Federal Transit Administration and Federal Highway Administration: Marcel Belanger, Donald Durkee, Paul Marx, Jeffrey Mora, Michael O’Connor, Terry Rosapep, and James Saklas. Special thanks go to Quon Y. Kwan, FTA Project Manager. We also thank the following people for their insights: John Maddox and William Coryell of North American Bus Industries, Paul Murphy of Motor Coach Industries, Mark Braeger of Orion Bus, George Husman of the Southern Research Institute, Tony Mascarin of IBIS Associates, Steve Misencik of TPI Composites, and David Klinikowski and Mustafa El-Gindy of the Altoona Bus Research and Testing Center. Volpe Center authors of the report include Scott Smith (Project Manager), John Brewer and Douglass Lee. Other contributions were made by William Chernicoff, Scott Lian, Matthew Rabkin, and Edward Ramsdell. Although these people and others contributed to the results of this study, the authors are solely responsible for any errors and omissions contained in this report. i Table of Contents Table of Contents .............................................................................................................. ii Tables ................................................................................................................................ iv Figures............................................................................................................................... vi Acronyms......................................................................................................................... vii Executive Summary.................................................................................................... ES-1 Chapter I: Background and Purpose...................................................................... I-1 Chapter II: Current Situation and Trends .............................................................II-1 II.1 Fleet Composition and Size ............................................................................ II-1 II.2 Vehicle Miles Traveled................................................................................... II-3 II.3 Weight Components and Trends..................................................................... II-6 Chapter III: Impacts of Overweight Buses......................................................... III-1 III.1 Pavement Damage ......................................................................................... III-1 III.2 Other Impacts............................................................................................... III-10 III.3 Conclusions.................................................................................................. III-12 Chapter IV: Lightweight Materials for Manufacturing Buses..........................IV-1 IV.1 Composite Materials ......................................................................................IV-1 IV.2 Issues with Composites..................................................................................IV-3 IV.3 Current and Potential Use of Composite Materials .......................................IV-5 IV.4 Conclusions....................................................................................................IV-6 Chapter V: Market Penetration of Lighter Weight Buses .................................... V-1 V.1 Life Cycle Costs.............................................................................................. V-2 V.2 Forces that Encourage Innovation .................................................................. V-5 V.3 Obstacles to Innovation................................................................................... V-5 V.4 Economic Viability of Lighter-weight Buses ................................................. V-6 V.5 Conclusions..................................................................................................... V-8 Chapter VI: Initial Review of Policy Alternatives..............................................VI-1 VI.1 Design of Policy Alternatives ........................................................................VI-1 VI.2 Estimating the Impacts of a Policy ................................................................VI-2 VI.3 Evaluation of Policy Alternatives ..................................................................VI-3 VI.4 Review of Proposed Policy Options ..............................................................VI-5 VI.5 Selection of Policy Options for Further Evaluation.....................................VI-16 Chapter VII: Benefit-Cost Evaluation of Selected Policies ............................... VII-1 VII.1 Policies to be Evaluated ...............................................................................VII-1 VII.2 Re-impose Weight Limits on Transit Buses.................................................VII-3 VII.3 Re-impose Weight Limits on Over-the-Road Motorcoaches.....................VII-12 VII.4 Expand the Current Permissive Arrangement to Interstate Transit Buses .VII-17 VII.5 Financial Incentives to Use Lighter Weight Transit Buses........................VII-18 VII.6 Financial Incentives to Use Lighter Weight OTR Buses ...........................VII-20 VII.7 Conclusions ................................................................................................VII-21 Chapter VIII: Recommendations.................................................................... VIII-1 Appendix 1: ESAL Weighted Load Factors......................................................... A-1 ii Appendix 2: Pavement Damage Cost as a Function of Empty Weight.............. A-5 Appendix 3: OTR Bus Benefits Versus Pavement Damage................................ A-7 Appendix 4: Glossary ............................................................................................. A-9 Appendix 5: References........................................................................................ A-11 iii Tables Table II-1 VMT (millions) by Highway Class (5)......................................................... II-4 Table II-2 1994 Vehicle Miles (millions) by Market Segment...................................... II-4 Table II-3 Public Transit Vehicle Miles (millions) (6)................................................. II-4 Table II-4 Vehicle Miles (millions) by Market Segment............................................... II-5 Table II-5 Bus Annual VMT by Highway Class (5) ..................................................... II-5 Table II-6 Estimated annual VMT by Highway Class and Market Segment ................ II-6 Table II-7 VMT by Registered and Operating Weight.................................................. II-7 Table II-8 Loaded Axle Weights (lbs) for 40-foot Transit Buses.................................. II-8 Table II-9 Axle Weights used in Kulakowski (15)........................................................ II-8 Table II-10 Alternate Fuel Impacts............................................................................... II-13 Table II-11 Major Contributors to Increased Transit Bus Weight............................... II-13 Table II-12 Major Contributors to Increased OTR Bus Weight.................................. II-15 Table III-1 Average Structural Number (SN) by Pavement Type................................. III-4 Table III-2 HERS Default Values for SN and D ........................................................... III-4 Table III-3 Flexible Pavement Restoration Costs per ESAL......................................... III-6 Table III-4 ESALs for Transit Buses and Motorcoaches............................................... III-8 Table III-5 Estimated Pavement Damage Cost per Vehicle Mile.................................. III-8 Table III-6 Estimated Bus Total Pavement Damage Cost............................................. III-9 Table III-7 Congestion Costs....................................................................................... III-10 Table III-8 External Crash Costs ................................................................................. III-11 Table III-9 Air Pollution Costs .................................................................................... III-11 Table III-10 Noise Costs.............................................................................................. III-12 Table V-1 Life Cycle Cost of Buses............................................................................... V-3 Table V-2 Assumed Price Premiums for Lighter-Weight Buses................................... V-7 Table VII-1 Policies to be Evaluated ............................................................................VII-1 Table VII-2 Benefit Categories.....................................................................................VII-1 Table VII-3 Smaller Transit Bus..................................................................................VII-4 Table VII-4 Impact of Smaller Buses on Operating Cost............................................VII-5 Table VII-5 Tag Axle Impact on Operating Cost ........................................................VII-6 Table VII-6 Lighter-Weight Transit Bus Scenarios.....................................................VII-6 Table VII-7 Lighter-Weight Transit Bus