The Oregon Department of Transportation performs load ratings to protect both the safety of traffic and the significant investment in the state’s bridge infrastructure.
A load rating that reflects the current condition of each bridge provides a valuable tool that is used in identifying the:
- Need for load posting or bridge strengthening;
- Making overweight-vehicle permit decisions;
- Prioritizing bridge repairs and replacements.
Load and Resistance Factor Rating
ODOT has implemented the Load and Resistance Factor Rating method, based on the 2011 AASHTO Manual for Bridge Evaluation with the latest interim revisions. LRFR is a statistically-based, more accurate and defensible load rating than the previous method, now referred to as the Tier-1 Load Rating Procedures.
All Oregon bridges, regardless of ownership, will be rated following the ODOT Load and Resistance Factor Rating procedures. ODOT bridges will use the Oregon-specific live load factors and all other bridges will use the re-calibrated national live load factors.