Extended Inspection Interval

Steel bridges where fatigue details have been verified may be considered for extended inspection intervals. Inspection intervals up to 48 months are allowed provided all the following criteria are met:
  • Year Built (Item B.W.01) ≥ 1979 [Year Built (Item 27) ≥ 1979] and fabricated in accordance with a fracture control plan.
  • NSTMs have no fatigue details with finite life, history of fatigue cracks, nor pin and hanger assemblies.
  • NSTM Inspection Condition (Item B.C.14) ≥ 6 [Superstructure Condition Rating (Item 59) ≥ 6, and Substructure Condition Rating (Item 60) ≥ 6]
  • Inventory Load Rating Factor (Item B.LR.05) ≥ 1.0 [Inventory Rating (Item 66) ≥ 1.0, when expressed as a rating factor or Item 66 must be greater than or equal to 36 when expressed in tons.]
  • Routine Permit Loads (Item B.LR.08) = A or N [Item 41 must be “A”]