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.

Or jump to Worst-rated By state About the data Methodology Guides
Bridges
575,638
Good
39%
Fair
41%
Deficient
6.1%

National Bridge Condition

Total Bridges

575,638

Tracked in the FHWA NBI

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

Bridge inventory deck-condition mix — National (FHWA NBI)

National38.66805179644152%40.75582223550217%GoodFairPoorStructurally Deficient
Bridge inventory deck-condition mix — National (FHWA NBI)

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.

US states ranked by structurally deficient bridge share Horizontal strip with one bar per state, sorted from lowest to highest SD share. Bars above the national average are highlighted in burnt sienna. Lowest SD Highest SD National avg 6.1% Each bar = one state, height = % structurally deficient. Source: FHWA NBI.

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

Poor

Over: SNAG CREEK

2.4 MI. S.E KY 1019, Bracken, KY

Built 1988 Load: 0.1 t ADT: 36

KY-415

Poor

Over: SMITH CREEK

.40 MI SE JCT KY 350, Clinton, KY

Built 1985 Load: 0.1 t ADT: 220

Armory Hill

Poor

Over: Road Run Creek

_, Washington, KY

Built 1955 Load: 0.1 t ADT: 1,410

N3248 (WALNUT ST.)

Poor

Over: RUSH CREEK (WALNUT ST.)

0.5 MI SE OF COURTHOUSE, Garvin, OK

Built 1920 Load: 0.1 t ADT: 4,200

WIDS ROAD

Structurally Deficient

Over: WHITE OAK CREEK

100' NE OF JCT CR 5156, Adair, KY

Built 1971 Load: 0.1 t ADT: 10

PETROLEUM RD

Structurally Deficient

Over: LITTLE TRAMMEL CREEK

0.2 MI. E JCT US 31E, Allen, KY

Built 1975 Load: 0.1 t ADT: 164

DEERFIELD ROAD

Structurally Deficient

Over: STOVALL CREEK

.7 MI W OF JCT KY 802, Ballard, KY

Built 1988 Load: 0.1 t ADT: 40

KY-3042

Structurally Deficient

Over: DIX RVR-HERRINGTON LAKE

.05 MI EAST OF KY34, Boyle, KY

Built 1924 Load: 0.1 t ADT: 630

Jones Branch

Structurally Deficient

Over: 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 Deficient

Over: 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

State condition rankings

Every state ranked by structurally deficient and poor-condition rate.

 Interactive tools

Look up a bridge, compare two states, or decode a condition rating.

 Research & analysis

Original studies of the NBI: largest inventories, materials, county concentration.

Frequently Asked Questions

What does "structurally deficient" mean?

A structurally deficient (SD) bridge has one or more key elements rated 4 or below on a 0–9 scale, or has a sufficiency rating under 50. 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 1978. 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 sufficiency rating (0–100) is a composite score considering structural adequacy, functional obsolescence, and essentiality.

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.

America's Aging Bridge Infrastructure

In-depth guide with context and practical steps.

How Bridge Repair Gets Funded

In-depth guide with context and practical steps.

How Bridge Inspections Work

In-depth guide with context and practical steps.

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 Good / Fair / Poor categories are derived, and how the sufficiency score is calculated.

 Guide

What "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.

 Method

Our data methodology

Source files, refresh cadence, sufficiency-rating formula, and the limits of the federal NBI dataset.