Detailed Bridge Inventory

The National Bridge Inventory(NBI) is authorized by statute, 23 U.S.C. 151 (National Bridge Inspection Program), and implemented by regulation, 23 CFR 650.301 et seq. In accord with these authorities, the Federal Highway Administration (FHWA) established National Bridge Inspection Standards (NBIS) for the safety inspection and evaluation of highway bridges; and each State is required to conduct periodic inspections of all bridges subject to the NBIS, prepare and maintain a current inventory of these structures, and report the data to the FHWA using the procedures and format outlined in the Recording and Coding Guide for the Structure Inventory and Appraisal of the Nation's Bridges.

After evaluation of the inspection data, the FHWA provides states with a list of bridges that are eligible for replacement or rehabilitation. The FHWA uses the data to submit a required biannual report to Congress on the status of the bridges, to publish an Annual Materials Report on New Bridge Construction and Bridge Rehabilitation in the Federal Register, and to apportion funds for the Highway Bridge Program.

Use of the NBI data also enables FHWA to satisfy its requirements under 23 U.S.C. 144, which mandate the inventory, classification, cost estimates for replacement or rehabilitation, and assignment of replacement or rehabilitation priorities for all highway bridges on all public roads.

For additional information, see the U.S. Department of Transportation.