Total Bridges
575,638
Tracked in the FHWA NBI
FHWA National Bridge Inventory · 575,638 bridges · 6.1% structurally deficient
Is your bridge
safe to cross?
Condition ratings, load ratings, and structural-deficiency data for 575,638+ public highway bridges. Searchable by state, county, and span. Sourced directly from the FHWA NBI.
- Bridges
- 575,638
- Good
- 39%
- Fair
- 41%
- Deficient
- 6.1%
Structurally deficient rate share of each state's bridges rated poor
See all states & territories → National Bridge Condition
Good Condition
38.7%
222,588 bridges rated 7-9
Fair Condition
40.8%
234,606 bridges rated 5-6
Structurally Deficient
6.1%
35,044 bridges with an element rated 4 or below
2024 NBI release
National Condition Distribution
Source: FHWA National Bridge Inventory · 35,044 structurally deficient bridges
State-by-state structural deficiency strip
Each tick = one US state, sorted from lowest to highest SD share. Burnt-sienna marks states above the national average.
What the inventory reveals
Four signals computed across all 46 large-inventory states, each opens the analysis behind it.
3×
Iowa has the highest deficiency rate — 3× the national average
65 yrs
Hawaii's bridges average 65 years old, the nation's oldest inventory
29,082
vehicles per day cross the average California bridge — the heaviest traffic load nationally
38.7%
of all 575,638 US bridges are rated in good condition (7–9 on the NBI scale)
Bridges Needing Most Attention
View rankings →Bridges in poor or structurally deficient condition nationally, ordered by their NBI inventory load rating, the lowest-rated, most load-restricted spans first.
KY-1951
PoorOver: SNAG CREEK
2.4 MI. S.E KY 1019, Bracken, KY
Built 1988 Load: 0.1 t ADT: 36
KY-415
PoorOver: SMITH CREEK
.40 MI SE JCT KY 350, Clinton, KY
Built 1985 Load: 0.1 t ADT: 220
Armory Hill
PoorOver: Road Run Creek
_, Washington, KY
Built 1955 Load: 0.1 t ADT: 1,410
N3248 (WALNUT ST.)
PoorOver: RUSH CREEK (WALNUT ST.)
0.5 MI SE OF COURTHOUSE, Garvin, OK
Built 1920 Load: 0.1 t ADT: 4,200
WIDS ROAD
Structurally DeficientOver: WHITE OAK CREEK
100' NE OF JCT CR 5156, Adair, KY
Built 1971 Load: 0.1 t ADT: 10
PETROLEUM RD
Structurally DeficientOver: LITTLE TRAMMEL CREEK
0.2 MI. E JCT US 31E, Allen, KY
Built 1975 Load: 0.1 t ADT: 164
DEERFIELD ROAD
Structurally DeficientOver: STOVALL CREEK
.7 MI W OF JCT KY 802, Ballard, KY
Built 1988 Load: 0.1 t ADT: 40
KY-3042
Structurally DeficientOver: DIX RVR-HERRINGTON LAKE
.05 MI EAST OF KY34, Boyle, KY
Built 1924 Load: 0.1 t ADT: 630
Jones Branch
Structurally DeficientOver: South Fk Quicksand Creek
100' S of KY 1098 MP 9.23, Breathitt, KY
Built 2013 Load: 0.1 t ADT: 55
TOY SPRING SCHOOL
Structurally DeficientOver: DALLAM CREEK
0.9 MI EAST OF JCT KY 106, Butler, KY
Built 1950 Load: 0.1 t ADT: 23
Browse by State
All states →AL
Alabama
3.3% SD
AK
Alaska
10.1% SD
AZ
Arizona
1.4% SD
AR
Arkansas
4.7% SD
CA
California
4.6% SD
CO
Colorado
4.3% SD
CT
Connecticut
4.0% SD
DE
Delaware
1.3% SD
DC
District of Columbia
1.3% SD
FL
Florida
2.8% SD
GA
Georgia
1.5% SD
GU
Guam
15.3% SD
HI
Hawaii
6.5% SD
ID
Idaho
5.5% SD
IL
Illinois
7.9% SD
IN
Indiana
4.9% SD
IA
Iowa
20.0% SD
KS
Kansas
5.2% SD
KY
Kentucky
7.1% SD
LA
Louisiana
11.0% SD
ME
Maine
13.2% SD
MD
Maryland
4.3% SD
MA
Massachusetts
8.0% SD
MI
Michigan
8.9% SD
MN
Minnesota
3.6% SD
MS
Mississippi
5.9% SD
MO
Missouri
8.5% SD
MT
Montana
6.7% SD
NE
Nebraska
7.7% SD
NV
Nevada
1.1% SD
NH
New Hampshire
7.1% SD
NJ
New Jersey
4.6% SD
NM
New Mexico
7.6% SD
NY
New York
6.9% SD
NC
North Carolina
6.2% SD
ND
North Dakota
10.8% SD
OH
Ohio
4.5% SD
OK
Oklahoma
7.5% SD
OR
Oregon
4.5% SD
PA
Pennsylvania
10.5% SD
PR
Puerto Rico
12.0% SD
RI
Rhode Island
7.7% SD
SC
South Carolina
6.1% SD
SD
South Dakota
16.2% SD
TN
Tennessee
4.0% SD
TX
Texas
1.1% SD
UT
Utah
2.4% SD
VT
Vermont
2.6% SD
VI
Virgin Islands
29.2% SD
VA
Virginia
3.0% SD
WA
Washington
4.8% SD
WV
West Virginia
16.0% SD
WI
Wisconsin
6.1% SD
WY
Wyoming
5.4% SD
Bridge Safety Guides
Structurally Deficient Bridges
What the designation means, how it's determined, and which states have the most
Bridge Safety Ratings Explained
Understanding NBI condition ratings, load ratings, and what they mean for drivers
How to Report an Unsafe Bridge
Step-by-step guide for reporting bridge concerns to your state DOT
Go deeper into the inventory
Frequently Asked Questions
What does "structurally deficient" mean?
Under the current federal definition, a structurally deficient (SD) bridge has at least one key element, deck, superstructure, substructure, or culvert, rated 4 or below ("Poor") on the 0–9 NBI scale. (An older definition also counted a sufficiency rating below 50, but the FHWA removed that criterion in 2018, so PlainBridge classifies SD strictly from condition ratings.) It does NOT necessarily mean the bridge is unsafe to drive on, it means the bridge needs repair or replacement and receives additional scrutiny from inspectors.
Where does this data come from?
All data comes from the Federal Highway Administration (FHWA) National Bridge Inventory (NBI) - a federal database mandated by Congress since 1968. States are required to inspect all public bridges every two years and report condition data to FHWA.
How are bridge conditions rated?
Bridge inspectors rate key elements, deck, superstructure, and substructure, on a 0–9 scale where 9 is excellent and 0 is failed condition. The overall condition category (Good/Fair/Poor) is derived from these element ratings. The FHWA historically published a 0–100 sufficiency rating combining structural adequacy, functional obsolescence, and essentiality; it no longer publishes that composite, but PlainBridge recomputes it from the NBI items using the FHWA formula and shows it on each bridge page alongside the condition ratings.
Is this free to use?
Yes. PlainBridge is completely free to use, ad-supported. All bridge data from the NBI is public domain US government data.
Related Guides
Editorial context for the plainbridges dataset, methodology, comparisons, and deep dives into the underlying records.
How to read NBI condition data
Bridge inspectors rate three primary elements, deck, superstructure, and substructure, on a 0–9 scale. The composite condition (Good / Fair / Poor) and the structurally-deficient (SD) flag are derived from those element ratings plus a sufficiency rating that factors in functional adequacy. The links below open the relevant guide pages on this site, all written and reviewed by the PlainBridges editorial team.
Guide
NBI condition ratings explained
What the 0–9 scale measures, how the Good / Fair / Poor categories are derived, and how PlainBridge computes the sufficiency rating.
GuideWhat "structurally deficient" actually means
SD does not mean unsafe to cross. It means at least one element is rated 4 or below, triggering FHWA priority for repair funding.
MethodOur data methodology
Source files, refresh cadence, sufficiency-rating formula, and the limits of the federal NBI dataset.
About this data
How PlainBridge works, and why you can trust these numbers
What this site is
PlainBridge covers 575,000+ public highway bridges across all 50 states plus territories, sourced entirely from the Federal Highway Administration (FHWA) National Bridge Inventory (NBI), the federal database mandated by Congress since 1968 following the Silver Bridge collapse. Every public highway bridge over 20 feet in the U.S. is required to be inspected and reported to the NBI, and PlainBridge presents that data without modification.
Editorial process
- Source. Download the annual NBI dataset directly from FHWA and parse all 116 standardized data items per bridge, including condition ratings, structural details, traffic counts, and geographic data.
- Verify. Apply FHWA's official condition classification (Good/Fair/Poor) and structurally-deficient definition exactly as published; where PlainBridge recomputes the discontinued sufficiency-rating composite, we validate it against the FHWA's historically reported national average and leave a rating blank rather than estimate a missing input.
- Publish. Update the database each spring when FHWA releases the new annual NBI dataset, and organize the records into searchable pages by bridge, county, and state.
Editorial independence & corrections
PlainBridge presents FHWA data without modification; condition ratings, inventory load ratings, and structural classifications are displayed exactly as reported in the NBI. Found a figure that looks wrong? Reach us at hello@plainbridges.com or through the contact page and we will verify against the NBI source data. See our methodology for the full condition-rating and sufficiency-rating calculation approach.
Frequently asked
What does "structurally deficient" mean?
Under the current federal definition, a structurally deficient (SD) bridge has at least one key element, deck, superstructure, substructure, or culvert, rated 4 or below ("Poor") on the 0–9 NBI scale. (An older definition also counted a sufficiency rating below 50, but the FHWA removed that criterion in 2018, so PlainBridge classifies SD strictly from condition ratings.) It does NOT necessarily mean the bridge is unsafe to drive on, it means the bridge needs repair or replacement and receives additional scrutiny from inspectors.
Where does this data come from?
All data comes from the Federal Highway Administration (FHWA) National Bridge Inventory (NBI) - a federal database mandated by Congress since 1968. States are required to inspect all public bridges every two years and report condition data to FHWA.
How are bridge conditions rated?
Bridge inspectors rate key elements, deck, superstructure, and substructure, on a 0–9 scale where 9 is excellent and 0 is failed condition. The overall condition category (Good/Fair/Poor) is derived from these element ratings. The FHWA historically published a 0–100 sufficiency rating combining structural adequacy, functional obsolescence, and essentiality; it no longer publishes that composite, but PlainBridge recomputes it from the NBI items using the FHWA formula and shows it on each bridge page alongside the condition ratings.
Is this free to use?
Yes. PlainBridge is completely free to use, ad-supported. All bridge data from the NBI is public domain US government data.