Methodology for Assigning Load Factors for AASHTO Rating Vehicle
The Federal Highway Administration (FHWA) is requiring the addition of three new bridge load rating vehicles (TYPE 3, TYPE 3S2, TYPE 3-3,) listed in the Bridge Design Manual (BDM) SECTION 908.3 as part of the new federal Specifications for the National Bridge Inventory (SNBI) to be completed by 2027. SNBI will require all Ohio bridges having an opening measured along the center of the roadway of more than 20 feet to be reanalyzed. The consensus among many structural engineers is that the impact these new vehicles would have on load ratings will be significantly less than the 10 vehicles (HL93/HS20, 2F1, 3F1, 5C1, SU4, SU5, SU6, SU7, PL60T, PL65T) listed in the BDM SECTION 908.2 and 908.3, already required to be analyzed resulting in an overall negligible impact. The impact on counties and municipalities to incorporate the new vehicles would be extremely costly as consultants would have to be hired to perform calculations of the three new vehicle types for all bridges within that jurisdiction. To comply with the updated SNBI federal requirements, research is needed to provide scientific evidence of the impact of the new load rating vehicles. The research would develop protocol(s) to assign new load rating factors based upon the existing 10 vehicles for bridge types, span configurations, number of lanes and other governing factors for the three new vehicles. A primary factor in the development of this research is to limit or eliminate the need to laboriously, systematically, and costly reload ratings all bridges. Findings from this research will be presented to FHWA for consideration. Acceptance of the protocol will assist Local Public Agencies (LPAs) in meeting the deadline for updating the load ratings in a reliable, accurate, expeditious and fiscally responsible manner while ensuring the integrity and safety of Ohio's local transportation system. The goal of this research is to assist counties and municipalities in meeting the new load rating vehicle federal requirements. Scientific evidence of the impact of the new load rating vehicles on specific bridge types accompanied with a simplified, statistically valid, reliable and repeatable methodology, if accepted by FHWA, could save locals substantial time and costs.
Language
- English
Project
- Status: Active
- Funding: $130,738.69
-
Contract Numbers:
43201
123396
137003
-
Sponsor Organizations:
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC United States 20590 -
Managing Organizations:
Ohio Department of Transportation
Research Program
1980 West Broad Street
Columbus, OH United States 43223 -
Project Managers:
Fout, Vicky
-
Performing Organizations:
Ohio University, Athens
Department of Civil and Environmental Engineering
Athens, OH United States 45701 -
Principal Investigators:
Sung, Min Soo
- Start Date: 20251101
- Expected Completion Date: 20261101
- Actual Completion Date: 0
Subject/Index Terms
- TRT Terms: Bridge design; Load factor; Methodology; Vehicles
- Subject Areas: Bridges and other structures; Design; Highways;
Filing Info
- Accession Number: 01969339
- Record Type: Research project
- Source Agency: Ohio Department of Transportation
- Contract Numbers: 43201, 123396, 137003
- Files: RIP, STATEDOT
- Created Date: Oct 24 2025 3:02PM