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Current Updates
- SIIMS Training SNBI Implementation (791.7 KB) Archived .pdf
- 2023 ICEA Conference: Basics of SIIMS (2.32 MB) Archived .pdf
- June 2023 SIIMS Update (182.72 KB) Archived .pdf
Federal Highway Administration (FHWA) Memoranda
- 1985 - Permits over 80,000 pounds allowed on Interstate highways (38.43 KB) Archived .pdf
- 1993 - Requirements for using Load Factor Rating Method (221.44 KB) Archived .pdf
- 2004 – Rating Method codes for NBI reporting (90.28 KB) Archived .pdf
- 2006 – When can ASR vs. LFR vs. LRFR be used (105.78 KB) Archived .pdf
- 2011 - Revisions to NBI items 31, 63, and 65 (63.96 KB) Archived .pdf
- 2011 – Revision to Rating Method codes for NBI reporting (38.12 KB) Archived .pdf
National Bridge Inspection Standards (NBIS)
- Load Ratings for NBIS and SNBI Compliance
- NBIS Metrics (77.3 KB) Archived .pdf
- NBIS 2005 (143.88 KB) Archived .pdf
- FHWA's FAQ on the NBIS (143.63 KB) Archived .pdf
- Recording and Coding Guide for the Structure Inventory and Appraisal (831.91 KB) Archived .pdf
- Input Procedures for FHWA Metrics (31.91 KB) Archived .pdf
Underwater Inspection Procedures
Back to topBrR Iowa Standard Templates - Updated February 2026
Training
- Iowa BrR Virtual Training 1 - General BrR
- Iowa BrR Virtual Training 2 - CMP Culverts and RC Box Culverts
- Iowa BrR Virtual Training 3_ Iowa DOT Template Models
- Iowa BrR Virtual Training 4_Modeling Steel Bridges
- Iowa BrR Virtual Training 5_Modeling Prestress Bridges
- Iowa BrR Virtual Training 6_Modeling RC Slab Bridges
- Iowa BrR Virtual Training 7_Performing Analyses
- AASHTOWare Bridge Rating Training Material
Template Information
- TR-832_Status on Template Completion (257.97 KB) .pdf
- TR-832 Load Rating for Standard Bridges (Completed to Date as of 2-11-2026) (74.26 MB) .pdf
- BrR Templates
- Library and System Files
- Supporting Calcs
Load Ratings for Standard Bridges
- Iowa Load Rating Vehicles (87.74 KB) .pdf
- Phase 1 – 1982 ASR Rating Method (1.21 MB) Archived .pdf
- Phase 2 – 1991 ASR Rating Method (656.22 KB) Archived .pdf
- Phase 3 – 1998 ASR Rating Method (1.73 MB) Archived .pdf
- Phase 4 – 2008 LFR Rating Method (293.04 KB) Archived .pdf
- Phase 5 – 2016 LFR Rating Method (685.66 KB) Archived .pdf
- Amendment to Phase 4 for SHV ratings
- Concrete Box Beam Standards (196.01 KB) Archived .pdf
- Phase 6 - 2021 Load Rating for Standard Bridges (1.33 MB) Archived .pdf
Load Ratings for Standard Culverts
- 2012 Cast in Place Culvert LRFR Ratings (667.33 KB) Archived .pdf
- 2013 Single Precast RCB Std LRFR Ratings (265.44 KB) Archived .pdf
- 2020 Cast in Place Culvert LRFR Ratings (457.15 KB) Archived .pdf
- 2020 Single Precast RCB Std LRFR Ratings (777.04 KB) Archived .pdf
Load Rating Tools for Concrete Box Culverts
Back to topLARS Input and File Upload Requirements
Back to topIowa DOT Maintenance and Inspection Manuals
- Bridge Inspection Manual
- Bridge Maintenance Manual (2.01 MB) Archived .pdf
- Bridge Rating Manual (6.46 MB) Archived .pdf
- Emergency Response Manual (11.19 MB) Archived .pdf
Training Videos
- March 2025 Inspection Manual for LPAs Webinar Recording
- SNBI Training Video
- May 2023 SIIMS Webinar Recording
- May 2023 SIIMS Webinar Presentation (2.62 MB) Archived .pdf
- Finding Structures
- Information Available in SIIMS for Structures
- Data Update Inspection Type
- Under Water Inspection Form
Other Information
- Listing of Bridge Inspection Agencies (16.75 KB) .xlsx
- County and City Engineer's Form 107 Download
- Instructional Memorandum 7.020 Bridge Inspections
- History of Load Rating (981.05 KB) .pdf