Proposed New AASHTO Load Rating Provisions for Implements of Husbandry

The size, geometry, and weight of farm equipment known as implements of husbandry (IoH) have increased and changed significantly to meet the needs of the modern agricultural industry. While intended primarily for use on the farm or in the field, frequently IoH travel on roads and bridges. Through a review of the history of bridge design vehicles as well as the evolution of truck size and weight legislation, it is clear that the growth of IoH has far out-paced legal vehicles.  Bridges are designed based on the AASHTO live loads that are different from IoH. Therefore, research is needed to provide guidance to help bridge owners and engineers load rate bridges for IoH in order to ensure public safety and preserve bridges. The objectives of this research were to (1) propose new implements of husbandry (IoH) load rating provisions for the AASHTO Manual for Bridge Evaluation (load factor rating “LFR” and load and resistance factor rating “LRFR”) and related revisions to the AASHTO LRFD Bridge Design Specifications; and (2) develop a set of protocols to evaluate IoH with various configurations for load rating and overload permits.


  • English


  • Status: Completed
  • Funding: $566864
  • Contract Numbers:

    Project 12-110

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Dekelbab, Waseem

  • Performing Organizations:

    E&T Consulting Engineers

    Chicago, IL  United States 
  • Principal Investigators:

    Fu, Gongkang

  • Start Date: 20161021
  • Expected Completion Date: 20191020
  • Actual Completion Date: 20191020
  • Source Data: RiP Project 40206

Subject/Index Terms

Filing Info

  • Accession Number: 01572393
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 12-110
  • Files: TRB, RiP
  • Created Date: Aug 7 2015 1:01AM