Download the FHWA NBI extracts behind PlainBridges: national-bridge-statistics.csv · high-traffic-poor-bridges.csv. National reference on statistics.
Interactive · FHWA NBI
Bridge data tools
Three free tools built directly on the National Bridge Inventory: look up any structure, compare two states, or decode a condition rating into plain English.
- 623,216
- Bridges searchable
- 54
- States & territories
- 6.8%
- Poor condition
According to the Federal Highway Administration's 2024 National Bridge Inventory, every tool on this page reads the same public-domain federal extract. See our methodology for how ratings and rollups are derived.
PlainBridges runs three free tools directly on the FHWA's 2024 National Bridge Inventory: a lookup for any of 623,216 bridges, a two-state comparison, and a condition-rating decoder.
The lookup resolves a structure by number or location and returns its component ratings in plain English; the comparison puts two states' Poor shares and inventory ages side by side; the decoder turns a 0-9 component score into what inspectors mean by it. All three read the same public-domain federal release, and none of them is a live crossing-safety verdict.
Bridge lookup
Search the National Bridge Inventory by route, waterway, or place and open the full NBI record.
State comparison
Put two states side by side on Good and Poor condition share and inventory size.
Condition decoder
Enter deck, superstructure, and substructure ratings to see how FHWA classifies a bridge.
What a lookup actually returns
Every one of the 623,216 records in the registry carries a base entry, live traffic count, and load rating. Full deck, superstructure, and substructure ratings cover 75.5% of records; the remaining share are culvert-type structures, which the NBI rates with a single consolidated score instead of the three-part bridge triad.
Registry coverage by data layer
When the searchable inventory was built
Exclusive construction-year eras across all 623,216 NBI bridges these tools query, not a restatement of Poor share. Year unknown covers null or sentinel construction years.
On this register · 2024 NBI
According to the Federal Highway Administration's 2024 National Bridge Inventory.
The three tools read the same 623,216-record file. Iowa leads Poor share at 19.16% among 49 large inventories; Texas holds the largest catalog (56,729) at 1.23% Poor.
- 6.8%
- Poor nationwide
- 19.16%
- Iowa · highest share
- 1.14%
- Nevada · lowest share
- 56,729
- Texas inventory
Lookup, compare, and decode operate on the inspection record. Poor is not a live crossing decision.
How do these bridge tools work?
Where does the data come from?
Every result is queried live from the Federal Highway Administration's National Bridge Inventory, the federal database that catalogs every public highway bridge. Nothing is estimated or fabricated.
Are the tools free?
Yes. All three tools are free and ad-supported, and they run on public-domain U.S. government data you are free to reuse.
Does Poor condition mean a bridge is unsafe?
No. Poor is a recorded condition category, not a live crossing or closure decision. The condition decoder explains which component rating produces it.
Explore more
What to do with this
Pick the tool that matches the question you brought.
- Resolve a structure by route, waterway, or place and open its NBI record. Bridge lookup
- Put two states side by side on Poor share and inventory size. State compare
- Turn deck, superstructure, and substructure scores into Good/Fair/Poor. Condition decoder
These tools reprint FHWA inventory fields. They are not live crossing-safety verdicts.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Lookup, compare, and decoder outputs are computed from the same NBI extract as the rest of the site; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.