AASHTO Load Rating Provisions for Implements of Husbandry

Farm equipment, generally referred to as “implements of husbandry” (IoH), has been considered to be local vehicles on farms that do not use public roads often, if at all. As a result, state and local jurisdictions vary widely in managing IoH. Apparently, the growth of IoH has far outpaced that of other legal highway vehicles, warranting concern with bridge safety.

The TRB National Cooperative Highway Research Program's NCHRP Research Report 951: AASHTO Load Rating Provisions for Implements of Husbandry (1) proposes new IoH load-rating provisions for the AASHTO Manual for Bridge Evaluation in load factor rating and load and resistance factor rating (LRFR), along with related revisions to the AASHTO LRFD Bridge Design Specifications; and (2) develops protocols to evaluate IoH with various configurations for load rating and overload permits.