The National Bridge Inventory database contains detailed technical and engineering information about hundreds of thousands of bridges in the United States including year built, bridge design, condition and many other fields. Nationalbridges.com is the website that makes this information available to the public.
The National Bridge Inventory (NBI) is a compilation of bridge data supplied by the States to the FHWA for bridges located on public roads.
The Massroads National Bridge Inventory query and report website "NationalBridges.com" is owned and maintained by Alexander Svirsky.
Nationalbridges.com and Alexander Svirsky has no affiliation with the FHWA or any state DOT.
The FHWA National Bridge Inventory home page is here: http://www.fhwa.dot.gov/bridge/nbi.htm
Email me with any questions about the NBI database and I will try to answer them or get an answer for you.