State profile · Below national median SD

Idaho bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in Idaho — drawn straight from the FHWA National Bridge Inventory.

1,742
Public bridges
33.3%
Good condition
5.5%
Poor condition
5.5%
Structurally deficient

Total Bridges

1,742

Public highway bridges in Idaho

Good Condition

33.3%

580 bridges rated 7-9

-16.7pp vs 50% benchmark

Poor Condition

5.5%

96 bridges rated 0-4

Structurally Deficient

5.5%

96 bridges flagged for repair priority

-1.5pp vs national avg 7.0%

Idaho vs national bridge condition

Idaho — Good condition share 33.3%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Idaho — Structurally deficient share 18.4%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

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

Idaho33.295063145809415%55.166475315729045%GoodFairPoorStructurally Deficient
Bridge inventory deck-condition mix — Idaho (FHWA NBI)

Counties (44)

Ada 81 Adams 42 Bannock 25 Bear Lake 13 Benewah 15 Bingham 75 Blaine 39 Boise 41 Bonner 47 Bonneville 50 Boundary 52 Butte 14 Camas 26 Canyon 77 Caribou 12 Cassia 38 Clark 18 Clearwater 65 Custer 81 Elmore 45 Franklin 4 Fremont 46 Gem 16 Gooding 25 Idaho 130 Jefferson 55 Jerome 26 Kootenai 60 Latah 26 Lemhi 73 Lewis 6 Lincoln 16 Madison 27 Minidoka 19 Nez Perce 19 Oneida 2 Owyhee 20 Payette 9 Power 13 Shoshone 139 Teton 13 Twin Falls 35 Valley 82 Washington 25

Idaho vs nearby ranks

Adjacent states on the structurally deficient leaderboard (lower share = better)

States are ranked by share of bridges flagged structurally deficient — the FHWA classification for any span where deck, superstructure, or substructure carries a condition rating of 4 or below. Lower percentages indicate stronger maintenance funding and inspection follow-through. States here sit immediately above and below Idaho on the same metric.

20

Kansas

5.25% top marginal rate
Structure
Progressive
Burden @ $100K
$23,867

56

Wyoming

5.41% top marginal rate
Structure
Progressive
Burden @ $100K
$3,181
Selected

16

Idaho

5.51% top marginal rate
Structure
Progressive
Burden @ $100K
$1,742

28

Mississippi

5.92% top marginal rate
Structure
Progressive
Burden @ $100K
$16,823

45

South Carolina

6.10% top marginal rate
Structure
Progressive
Burden @ $100K
$5,396

Bridges Needing Most Attention in Idaho

Six lowest-condition bridges in Idaho, ranked by composite NBI rating. Each is inspected at least every 24 months.

STC 6774;TETON HWY

Poor

Over: S.FK.TETON RIVER

0.5 N. TETON, Fremont, ID

Built 1977 Load: 0.9 t ADT: 1,200

SWAMP ROAD

Poor

Over: CAMAS CREEK

1.5 S. 0.3 E. HILL CITY, Camas, ID

Built 1965 Load: 1.8 t ADT: 40

ROAD 50343

Poor

Over: LOGAN CREEK

NO DATA ENTERED, Valley, ID

Built 1980 Load: 2.6 t ADT: 50

VADNAIS LANE

Poor

Over: CAMAS CREEK

1.9 S. 0.6 E. KILGORE, Clark, ID

Built 1981 Load: 2.7 t ADT: 50

2701: NORTH MILNER

Poor

Over: Milner Gooding Canal

5.0 mi N of Hunt Rd, Jerome, ID

Built 1960 Load: 4.2 t ADT: 25

MIDDLE FORK ROAD

Structurally Deficient

Over: M.FK.WEISER RIVER

7.3 W 3.4 S DONNELLY, Adams, ID

Built 1957 Load: 4.5 t ADT: 70

All Bridges in Idaho

2701: NORTH MILNER

Poor

Over: Milner Gooding Canal

5.0 mi N of Hunt Rd, Jerome, ID

Built 1960 Load: 4.2 t ADT: 25

2350 NORTH

Poor

Over: CAMAS CREEK

2.5 N. 2.9 W. HAMER, Jefferson, ID

Built 1972 Load: 4.5 t ADT: 20

850 WEST ROAD

Poor

Over: MILNER GOODING CANAL

6.5 N. 8.4 W. SHOSHONE, Lincoln, ID

Built 1950 Load: 7.3 t ADT: 20

AVELENE CK. ROAD

Poor

Over: GRIMES CREEK

9 MI SW OF IDAHO CITY, Boise, ID

Built 1954 Load: 9.1 t ADT: 20

S 100 E

Poor

Over: CLOVER CREEK

6.0 W 5.0 N BLISS, Gooding, ID

Built 1985 Load: 9.1 t ADT: 30

SAGE ROAD

Poor

Over: SUCCOR CREEK

1.0 S. 3.8 W. HOMEDALE, Owyhee, ID

Built 1930 Load: 10.0 t ADT: 90

3214: RUIZ LAKE

Poor

Over: Dietrich Main Canal

3.2 mi E of ID93, Lincoln, ID

Built 1987 Load: 10.4 t ADT: 25

ROSE GARDEN RD

Poor

Over: NOTUS CANAL

CALDWELL;ROSE GARDEN RD, Canyon, ID

Built 1935 Load: 10.9 t ADT: 600

990 SOUTH ROAD

Poor

Over: 'C' CANAL

1.3 S. 2.5 E. HAZELTON, Jerome, ID

Built 1962 Load: 10.9 t ADT: 160

S 1000 W

Poor

Over: TRAIL CREEK

0.1 N. 0.5 W. VICTOR, Teton, ID

Built 1995 Load: 10.9 t ADT: 60

2050 EAST ROAD

Poor

Over: LITTLE WOOD RIVER

0.1 S. 1.5 E. GOODING, Gooding, ID

Built 1930 Load: 11.8 t ADT: 20

OLD HORNET ROAD

Poor

Over: HORNET CREEK

3.5 N. 3.5 W. COUNCIL, Adams, ID

Built 1949 Load: 13.6 t ADT: 100

FS ROUTE NO. 537

Poor

Over: BIG CREEK

BIG CREEK, Shoshone, ID

Built 1939 Load: 13.6 t ADT: 50

FOREST ROAD 2038

Poor

Over: SLATE CREEK

NO DATA ENTERED, Idaho, ID

Built 1953 Load: 14.3 t ADT: 50

DIVERSION ROAD

Poor

Over: CAMAS CREEK

10.7 S. 1.2 W. KILGORE, Clark, ID

Built 1953 Load: 14.5 t ADT: 50

OLD MIL. RR GRADE

Poor

Over: SLOUGH BRIDGE

1.4N 3.1W CALDER, Shoshone, ID

Built 1912 Load: 14.5 t ADT: 15

FS ROUTE N0. 413

Poor

Over: N.F. CDA RIVER

BREAKWATER, Kootenai, ID

Built 1950 Load: 14.6 t ADT: 50

2421: ASTORQUIA RO

Poor

Over: Twin Falls N. Side Canal

5.0 mi E of ID46, Gooding, ID

Built 1964 Load: 14.9 t ADT: 25

STC 6760;RED ROAD

Poor

Over: CAMAS CREEK

8.1 S. 0.4 W. KILGORE, Clark, ID

Built 1953 Load: 15.4 t ADT: 360

NORTH BIRCH STREET

Poor

Over: LITTLE WOOD RIVER

IN SHOSHONE;N.BIRCH ST, Lincoln, ID

Built 1913 Load: 15.4 t ADT: 200

N 4400 E (SHELTON)

Poor

Over: BURGESS CANAL

4.7 E. 0.6 S. RIGBY, Jefferson, ID

Built 1969 Load: 16.3 t ADT: 510

N. ST. CHARLES

Poor

Over: LEMHI RIVER

0.4 N. 0.3 E. SALMON, Lemhi, ID

Built 1948 Load: 16.3 t ADT: 310

NO DATA ENTERED

Poor

Over: PANTHER CREEK

NO DATA ENTERED, Lemhi, ID

Built 1980 Load: 17.2 t ADT: 200

FS ROUTE NO. 409

Poor

Over: W.F. STEAMBOAT CREEK

W FK STEAMBOAT CR, Shoshone, ID

Built 1956 Load: 17.2 t ADT: 50

SHEEP CAMP RD

Poor

Over: GRANDVIEW IRRIGATION CNL

1.3 E. GRANDVIEW, Owyhee, ID

Built 1991 Load: 18.1 t ADT: 60

FDR

Poor

Over: SOUTH FORK BOISE RIVER

SKUNK CREEK-SO FK JUNCT., Camas, ID

Built 1989 Load: 19.1 t ADT: 12

CUSTER MOTORWAY

Poor

Over: YANKEE FORK

NO DATA ENTERED, Custer, ID

Built 1992 Load: 19.1 t ADT: 100

NO DATA ENTERED

Poor

Over: NO DATA ENTERED

NO DATA ENTERED, Custer, ID

Built 1972 Load: 19.1 t ADT: 50

COTTONWD-BANNOCK

Poor

Over: MORES CREEK

1 MI ESE OF IDAHO CITY, Boise, ID

Built 1962 Load: 20.7 t ADT: 30

FS ROUTE NO. 456A

Poor

Over: N.F. ST JOE RIVER

LOOP CREEK, Shoshone, ID

Built 1935 Load: 20.7 t ADT: 50

1300 N

Poor

Over: HENRYS FK.SNAKE R;FRITZ

1.1 S. 4.0 W. ASHTON, Fremont, ID

Built 1967 Load: 21.8 t ADT: 50

EAST FORK ROAD

Poor

Over: S.FK.SALMON RIVER

14.5 W. YELLOW PINE, Valley, ID

Built 1940 Load: 21.8 t ADT: 40

BEAVER-LOON ROAD

Poor

Over: JORDAN CREEK

NO DATA ENTERED, Custer, ID

Built 1957 Load: 23.0 t ADT: 100

STC 5804;WESTSIDE

Poor

Over: MYRTLE CREEK

0.8N. 4.8W. BONNERS FERRY, Boundary, ID

Built 1958 Load: 23.6 t ADT: 300

BURNT LOG ROAD

Poor

Over: JOHNSON CREEK

.5 MI NW LANDMARK AIRSTRP, Valley, ID

Built 1977 Load: 23.7 t ADT: 30

BOULDER CREEK ROAD

Poor

Over: MORES CREEK

5 MI NE IDAHO CITY, Boise, ID

Built 1982 Load: 24.0 t ADT: 50

MOCCASIN-NAPIAS RD

Poor

Over: NAPIAS CREEK

NO DATA ENTERED, Lemhi, ID

Built 1953 Load: 24.3 t ADT: 25

OLD HWY 91

Poor

Over: UPRR;N.SPENCER RR OP

13.1 N. 5.2 W. SPENCER, Clark, ID

Built 1936 Load: 24.5 t ADT: 50

SQUAW CREEK RD

Poor

Over: SQUAW CREEK

2.9 W. CLAYTON, Custer, ID

Built 1960 Load: 25.2 t ADT: 100

NO DATA ENTERED

Poor

Over: OROFINO CREEK

MILL POND, Clearwater, ID

Built 1958 Load: 25.3 t ADT: 140

US 20 FRONTAGE RD

Poor

Over: FALL RIVER OVERFLOW

1.5 N. 3.7 E. ST ANTHONY, Fremont, ID

Built 1932 Load: 28.1 t ADT: 10

FS ROUTE NO. 2706

Poor

Over: GRANITE CREEK

GRANITE CREEK, Bonner, ID

Built 1964 Load: 28.2 t ADT: 50

FS ROUTE NO. 308

Poor

Over: KALISPELL CREEK

KALISPELL CREEK, Bonner, ID

Built 1955 Load: 28.8 t ADT: 50

PARKINSON ROAD

Poor

Over: CUB RIVER

IN FRANKLIN;PARKINSON RD., Franklin, ID

Built 1926 Load: 29.0 t ADT: 310

I 90 WBL

Poor

Over: PEDESTRIAN/BIKE PATH

COEUR D'ALENE NWCL, Kootenai, ID

Built 1971 Load: 29.0 t ADT: 31,500

PR

Poor

Over: NORTH FORK WOOD RIVER

2 MILES NORTH SNRA HQDS, Blaine, ID

Built 1950 Load: 29.2 t ADT: 50

NO DATA ENTERED

Poor

Over: YELLOWJACKET CREEK

NO DATA ENTERED, Lemhi, ID

Built 1962 Load: 29.8 t ADT: 50

NORTH APPLE STREET

Poor

Over: LITTLE WOOD RIVER

IN SHOSHONE;N.APPLE ST, Lincoln, ID

Built 1920 Load: 29.9 t ADT: 200

2416: TEAKETTLE RO

Poor

Over: Y-1 Canal

2.4 mi N of ID26, Gooding, ID

Built 1991 Load: 30.5 t ADT: 25

FDR 103

Poor

Over: YOOSA CREEK

YOOSA CREEK BRIDGE, Idaho, ID

Built 1963 Load: 30.5 t ADT: 40

Showing 1,651-1,700 of 1,742 bridges

Related

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Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges Editorial.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). A "structurally deficient" rating is a repair-priority signal, not a closure or unsafe-to-cross designation. Consult a qualified civil engineer before making decisions based on this data.

Understanding Bridge Conditions

How FHWA rates bridge condition on a 0-9 scale.

Check Your Daily Bridges

How to look up bridge condition data for bridges on your route.

Read our methodology — how this data is sourced, computed, and verified.