23 CFR 661.57 - How is a list of deficient bridges to be generated?
(a) In consultation with the BIA, a list of deficient BIA IRR bridges will be developed each fiscal year by the FHWA based on the annual April update of the NBI. The NBI is based on data from the inspection of all bridges. Likewise, a list of non-BIA IRR bridges will be obtained from the NBI. These lists would form the basis for identifying bridges that would be considered potentially eligible for participation in the IRRBP. Two separate master bridge lists (one each for BIA and non-BIA IRR bridges) will be developed and will include, at a minimum, the following:
(1) Sufficiency rating (SR);
(2) Status (structurally deficient or functionally obsolete);
(3) Average daily traffic (NBI item 29);
(4) Detour length (NBI item 19); and
(5) Truck average daily traffic (NBI item 109).
(b) These lists would be provided by the FHWA to the BIADOT for publication and notification of affected BIA regional offices, Indian Tribal governments (ITGs), and State and local governments.
(c) BIA regional offices, in consultation with ITGs, are encouraged to prioritize the design for bridges that are structurally deficient over bridges that are simply functionally obsolete, since the former is more critical structurally than the latter. Bridges that have higher average daily traffic (ADT) should be considered before those that have lower ADT. Detour length should also be a factor in selection and submittal of bridges, with those having a higher detour length being of greater concern. Lastly, bridges with higher truck ADT should take precedence over those which have lower truck ADT. Other items of note should be whether school buses use the bridge and the types of trucks that may cross the bridge and the loads imposed.