Program for Sustainable Pavement Engineering and Research

About the research

This project is a task order under the main Federal Highway Administration (FHWA)-sponsored project, “Infrastructure Research and Technology Deployment Program.”

The final report reviews state department of transportation (DOT) practices related to bridge load rating, posting, and permitting procedures, analyzing publicly available documents. It examines previous versions of the National Bridge Inspection Standards (NBIS) and the most recent 2022 update, alongside the American Association of State Highway and Transportation Officials (AASHTO) Manual for Bridge Evaluation (MBE) and its interim revisions. The review highlights both common and unique practices across states in assessing bridge load-carrying capacity, which is essential for preservation and public safety. Routine load ratings are typically based on design plans, field measurements, and inspection reports, while more advanced methods incorporate sophisticated analytical techniques like two-dimensional (2D) and three-dimensional (3D) finite element models.

In 2024, peer exchange meetings were held in Salt Lake City, UT, and Pittsburgh, PA, where participating transportation agencies discussed five key topics: state truck size and weight limits, consideration of deterioration in bridge load rating, timely re-rating and posting, structural analysis for permit loads, and research and technology. The final report summarizes the meetings and their contributions to advancing bridge load rating practices across the U.S.