Guide · FHWA NBI
“Structurally deficient” is a retired federal term
FHWA now reports bridges as Good, Fair, or Poor. Here is what changed, what Poor condition means, and what the federal record cannot tell you.
- 42,080
- Poor-condition bridges
- 6.8%
- Poor-condition share
- 623,216
- Bridges nationwide
"Structurally deficient" is a retired FHWA reporting status: since the 2018 archive, bridges are reported as Good, Fair or Poor instead.
A bridge is Poor when the lowest of its applicable deck, superstructure, substructure or culvert ratings is 4 or below on the inspecting agency's 0-9 scale; 5-6 is Fair and 7-9 is Good. 42,080 of the 623,216 bridges in the 2024 National Bridge Inventory are rated Poor. The category signals maintenance and funding priority, not that a bridge is closed or unsafe to cross.
On this register · 2024 NBI
According to the Federal Highway Administration's 2024 National Bridge Inventory.
FHWA retired “structurally deficient” in 2018. On the Poor replacement, Iowa leads share at 19.16% among 49 large inventories, while Texas's 56,729-bridge catalog is 1.23% Poor.
- 19.16%
- Iowa · highest Poor share
- 1.14%
- Nevada · lowest share
- 1.23%
- Texas · largest catalog
- 6.8%
- Poor nationwide
42,080 of 623,216 records are Poor. The category is maintenance priority in the inspection file, not a retired SD label and not a live closure.
Source: FHWA Bridge Condition terminology · Specifications for the National Bridge Inventory · 2024 NBI release
What happened to “structurally deficient”?
In July 2026, PlainBridges checked this terminology against the Federal Highway Administration's Bridge Condition table and current SNBI documentation. According to the agency, “structurally deficient” was eliminated from program use beginning with the 2018 archived data. The term still appears in older federal tables, news stories, and local reports, but current reporting uses three condition categories: Good, Fair, and Poor.
PlainBridges keeps this page at its established URL because people still search for the old term. Throughout current data pages, however, we use Poor condition. The database field names sd_count and is_structurally_deficient are retained only for backward compatibility and hold the current Poor-condition test.
How current condition categories work
For NBI component ratings on the 0–9 scale, PlainBridges follows the current federal thresholds:
- Good: the lowest applicable deck, superstructure, substructure, or culvert rating is 7–9.
- Fair: the lowest applicable rating is 5–6.
- Poor: the lowest applicable rating is 0–4.
A Poor category identifies a recorded component condition. It is not a live safety certification, closure order, prediction of failure, or statement about the cause of deterioration. Posting, restriction, and closure decisions belong to the responsible bridge owner and its engineers.
Why old reports can disagree with current data
FHWA changed both its terminology and its data specification. The agency also discontinued the calculated Sufficiency Rating and Status items. A historical report may therefore show an SD status or sufficiency score that has no current equivalent in the federal inventory.
PlainBridges may show a sufficiency score as a clearly labeled historical, recomputed reference. That score does not change the current Good/Fair/Poor result and should not be read as present-day funding eligibility, posting, or closure status.
Which materials carry the most Poor records
Poor-condition share isn't evenly spread across material families. Steel structures, many built mid-century and now approaching or past typical service life, carry a disproportionate share of Poor records relative to their share of the total inventory, more than concrete and prestressed concrete combined in absolute count.
Poor-condition bridges by material
Material-family breakdown among the 42,080 Poor-condition bridges in the 2024 NBI file, this is a subset of the full material mix, not the whole inventory.
This is a descriptive inventory measure, not a ranking of driver safety or agency performance. Bridge mix, ownership, environment, inspection timing, and the age and type of structures all differ across states and materials. Check the rankings page for the complete state-by-state breakdown and the 2024 release date attached to the comparison.
What this data cannot tell you
An annual federal inventory is not a live status feed. It cannot tell you whether a bridge is safe to cross at this moment, whether work occurred after the recorded inspection, or whether an emergency restriction has just been imposed. It also cannot substitute for an engineering evaluation.
- For current closures and restrictions, check the state DOT or bridge owner's official traveler-information service.
- For posted vehicle limits, obey signs at the bridge and verify with the owner.
- For visible damage or an immediate hazard, contact the responsible agency or emergency services.
Verify the definition
These official FHWA references document the terminology and the current reporting specification:
- FHWA bridge condition terminology, including the retirement of “Structurally Deficient.”
- FHWA SNBI questions and answers, including discontinued calculated items.
- Specifications for the National Bridge Inventory, the current reporting specification.
The Bottom Line
“Structurally deficient” is useful only as historical vocabulary. For current NBI data, use Poor condition: the lowest applicable major-component rating is 4 or below. Treat that as an inspection-record category, not a real-time answer about whether to cross.