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

SALMON RIVER ROAD

Good

Over: SALMON RIVER

SALMON RIVER NEAR COVE CR, Lemhi, ID

Built 2012 Load: 38.6 t ADT: 350

INDIAN CREEK ROAD

Good

Over: INDIAN CREEK

NO DATA ENTERED, Lemhi, ID

Built 2008 Load: 38.6 t ADT: 5

NO DATA ENTERED

Good

Over: INDIAN CREEK

NO DATA ENTERED, Lemhi, ID

Built 2008 Load: 38.6 t ADT: 5

NO DATA ENTERED

Good

Over: DITCH CREEK

NO DATA ENTERED, Lemhi, ID

Built 2008 Load: 38.6 t ADT: 10

IRR BIA RTE 59

Good

Over: BLACKFOOT RIVER

13 KM SW OF BLACKFOOT, Bingham, ID

Built 1990 Load: 38.7 t ADT: 110

FS ROUTE NO. 1007

Good

Over: SNOW CREEK

SNOW CREEK, Boundary, ID

Built 1972 Load: 38.9 t ADT: 50

NOTUS CANAL

Good

Over: I84 EBL WBL

IN CALDWELL, Canyon, ID

Built 2022 Load: 38.9 t ADT: 67,500

NO DATA ENTERED

Good

Over: CROOKED FORK CREEK

CROOKED FK-RD 111, Idaho, ID

Built 1970 Load: 38.9 t ADT: 50

FSR 107

Good

Over: GRAVE CREEK

NO DATA ENTERED, Idaho, ID

Built 2014 Load: 38.9 t ADT: 15

S FK SALMON

Good

Over: LODGEPOLE CREEK

5 MI N STOLLE MEADOWS, Valley, ID

Built 2008 Load: 38.9 t ADT: 50

I 84 EBL

Good

Over: NEW YORK CANAL

IN BOISE;NEAR ORCHARD ST., Ada, ID

Built 1968 Load: 39.0 t ADT: 44,500

LARSON ROAD

Good

Over: JIM FORD CR;SE WEIPPE BR

1.7 S. 1.0 E. WEIPPE, Clearwater, ID

Built 2015 Load: 39.0 t ADT: 30

STC2735;2900 E. RD

Good

Over: HIGH LINE CANAL

4 S. TWIN FALLS, Twin Falls, ID

Built 2006 Load: 39.0 t ADT: 820

IRR BIA RTE 68

Good

Over: BIG JIMMEY CREEK

15KM W FT HALL IN BOTTOMS, Bannock, ID

Built 2014 Load: 39.2 t ADT: 35

ADAMS GULCH ROAD

Good

Over: BIG WOOD RIVER

1.7 N. 0.5 W. KETCHUM, Blaine, ID

Built 2018 Load: 39.2 t ADT: 590

GRAND JEAN ROAD

Good

Over: CANYON CREEK

.25 MI N WAPITI CK TRACT, Boise, ID

Built 1972 Load: 39.2 t ADT: 80

HOOPER LANE

Good

Over: PAHSIMEROI RIVER

3.5 S 0.8 E MAY, Custer, ID

Built 2011 Load: 39.2 t ADT: 70

FDR

Good

Over: FOURTH OF JULY CREEK

5 MILES UP 4TH OF JULY RD, Custer, ID

Built 1992 Load: 39.2 t ADT: 100

FS ROUTE NO. 419

Good

Over: EF LIGHTNING CREEK

EF LIGHTNING CREEK, Bonner, ID

Built 2009 Load: 39.5 t ADT: 50

STC6707; E 97TH S

Good

Over: IDAHO CANAL

2.0 N 0.5 E TAYLORVILLE, Bonneville, ID

Built 2022 Load: 39.5 t ADT: 900

3040: ROCKY CANYON

Good

Over: Hawley Creek

8.4 mi E of ID28 N, Lemhi, ID

Built 2013 Load: 39.5 t ADT: 35

US 95

Good

Over: LAPWAI CREEK

2.0 N. 1.0 E. WINCHESTER, Lewis, ID

Built 2019 Load: 39.5 t ADT: 3,500

500 SOUTH ROAD

Good

Over: 'A-5' CANAL

0.7 S. 3.6 E. HEYBURN, Minidoka, ID

Built 2020 Load: 39.5 t ADT: 1,100

3708: DEEP CREEK

Good

Over: Current Creek

50.0 mi S of ID78, Owyhee, ID

Built 2017 Load: 39.5 t ADT: 25

ROAD 216

Good

Over: HOMESTEAD CREEK

SEC 29, T.44N., R.4E. BM, Shoshone, ID

Built 2018 Load: 39.5 t ADT: 50

IRR BIA RTE 901

Good

Over: OWYHEE RIVER

9.8 KM NW OWYHEE AGENCY, Owyhee, ID

Built 1987 Load: 39.7 t ADT: 20

STC 3856; FRANKLIN

Good

Over: FIVE MILE CREEK

IN MERIDIAN, Ada, ID

Built 2004 Load: 39.9 t ADT: 23,500

SH 21

Good

Over: MORES CR.;WILDCAT GULCH

8.5 S. IDAHO CITY, Boise, ID

Built 1990 Load: 39.9 t ADT: 2,000

NFSR 223

Good

Over: GLOVER CREEK

15 MILES FROM LOWELL, Idaho, ID

Built 2014 Load: 39.9 t ADT: 40

3501: EAGLE CREEK

Good

Over: Eagle Creek

11 mi S of Zaza Road, Nez Perce, ID

Built 1974 Load: 39.9 t ADT: 25

IRR BIA RTE 904

Good

Over: OWYHEE RIVER

17.4 KM NW OF OWYHEE, Owyhee, ID

Built 1987 Load: 40.0 t ADT: 20

FOREST ROAD 1858

Good

Over: NEWSOME CREEK

NEWSOME TOWN SITE, Idaho, ID

Built 1966 Load: 40.2 t ADT: 40

SH 78

Good

Over: SCORPION CREEK

5.7 N 0.6 W MURPHY, Owyhee, ID

Built 2013 Load: 40.2 t ADT: 1,200

NFSR 50446

Good

Over: FISHER CREEK TRIBUTARY

NO DATA ENTERED, Valley, ID

Built 1965 Load: 40.5 t ADT: 50

STC8200;JENKINS RD

Good

Over: GALLOWAY CANAL

0.9 N. 1.2 W. WEISER, Washington, ID

Built 1971 Load: 40.5 t ADT: 810

NO DATA ENTERED

Good

Over: EAST FORK WEISER RIVER

NO DATA ENTERED, Adams, ID

Built 1963 Load: 40.8 t ADT: 50

FS ROUTE NO. 2694

Good

Over: GOOSE CREEK

GOOSE CREEK, Bonner, ID

Built 1990 Load: 40.8 t ADT: 50

MORMON ROAD

Good

Over: CAMAS CREEK

3.8 S. 0.5 W. FAIRFIELD, Camas, ID

Built 2016 Load: 40.8 t ADT: 30

US 93

Good

Over: SALMON RIVER;CHALLIS BR.

2.6 S. CHALLIS, Custer, ID

Built 1995 Load: 40.8 t ADT: 1,400

CUSTER ROAD

Good

Over: SULPHUR CREEK

3.8 S. 0.2 W. MAY, Custer, ID

Built 2012 Load: 40.8 t ADT: 100

ZUMWALT ROAD

Good

Over: S.FK. COTTONWOOD CREEK

4.8 N. 3.0 W. GRANGEVILLE, Idaho, ID

Built 2017 Load: 40.8 t ADT: 50

FDR 103

Good

Over: CAMP CREEK

23 MILES FROM PIERCE, ID, Idaho, ID

Built 1968 Load: 40.8 t ADT: 30

US 95 NBL

Good

Over: FIGHTING CREEK

12.7 N. WORLEY, Kootenai, ID

Built 2006 Load: 40.8 t ADT: 3,350

60030

Good

Over: SALMON RIVER

SALMON RIVER NEAR PINE CR, Lemhi, ID

Built 2012 Load: 40.8 t ADT: 350

HANLEY PLACE

Good

Over: WILLOW CREEK

6.95 S. EMMETT, Ada, ID

Built 2023 Load: 41.1 t ADT: 40

DEADWD.-SCT.MT.RD.

Good

Over: EAST BIG PINE CREEK

4 MI NE DANSKIN, Boise, ID

Built 2007 Load: 41.1 t ADT: 15

FDR 595

Good

Over: CROOKED FORK

25 MILES TO POWELL R S, Clearwater, ID

Built 1972 Load: 41.1 t ADT: 30

NO DATA ENTERED

Good

Over: NO DATA ENTERED

WENDOVER CAMP GROUND, Idaho, ID

Built 2011 Load: 41.1 t ADT: 40

NFSR 50246

Good

Over: LAKE CREEK

NO DATA ENTERED, Idaho, ID

Built 1976 Load: 41.1 t ADT: 40

TRAPPER CREEK RD

Good

Over: TRAPPER CREEK

4.5 S. 0.8 E. PINEHURST, Shoshone, ID

Built 2021 Load: 41.1 t ADT: 30

Showing 1,451-1,500 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.