A Comparison of AASHTO Bridge Load Rating Methods

TRB’s National Cooperative Highway Research Program (NCHRP) Report 700: A Comparison of AASHTO Bridge Load Rating Methods documents an analysis of 1,500 bridges that represent various material types and configurations using AASHTOWare™ Virtis® to compare the load factor rating to load and resistance factor rating for both moment and shear induced by design vehicles, American Association of State Highway and Transportation Officials (AASHTO) legal loads, and eight additional permit/legal vehicles.

The report includes proposed revisions to the AASHTO Manual for Bridge Evaluation based on a review of the analysis results.

The appendixes to NCHRP Report 700 are not part of the printed version of the report. The appendixes are available in a single electronic document and are listed below. Please note that this is a very large document and may take a number of minutes to download.

• Appendix A—Final Bridge/Girder List

• Appendix B—Simple Span Steel Girder Bridges

• Appendix C—Simple Span Prestressed I-Girder Bridges

• Appendix D—Simple Span Prestressed Box Girder Bridges

• Appendix E—Simple Span Reinforced Concrete T-Beam Bridges

• Appendix F—Simple Span Reinforced Concrete Slab Bridges

• Appendix G—Steel I-Girder Continuous Span Bridges

• Appendix H—Continuous Reinforced Concrete Slab Bridges

• Appendix I—Continuous Prestressed I-Girder Bridges

• Appendix J—Calculated Reliability Indices

• Appendix K—Effect of Permit Type and ADTT on LRFR Ratings

• Appendix L—Effect of LRFR Rating on Operating Rating

• Appendix M—Effect of LRFR on Rating Using Proposed Load Factors

• Appendix N—MBE Examples

• Appendix O—Review of the NBI/Virtis Databases

• Appendix P—Final Survey

• Appendix Q—Changes required for NCHRP 12-50/Software Documentation

• Appendix R—Format of CSV output produced by RIO software