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

FS ROUTE 633

Good

Over: JIM CREEK

JIM CREEK, Boundary, ID

Built 2010 Load: 31.4 t ADT: 40

FS ROUTE 209

Good

Over: N.F. CDA RIVER

N.F. CDA RIVER, Kootenai, ID

Built 1958 Load: 31.4 t ADT: 40

400 North Road

Good

Over: Main Northside Canal

4.0 N 9.3E. RUPERT, Minidoka, ID

Built 1980 Load: 31.6 t ADT: 120

STC 3784;E KUNA RD

Good

Over: NEW YORK CANAL

3.4 E. KUNA, Ada, ID

Built 1977 Load: 31.8 t ADT: 2,600

US 20

Good

Over: LOVING CREEK

11.6 W. CAREY, Blaine, ID

Built 1971 Load: 31.8 t ADT: 1,800

I 84 EBL

Good

Over: CANYON CREEK

5.5 W. MOUNTAIN HOME, Elmore, ID

Built 1959 Load: 31.8 t ADT: 14,000

HIGH TOP LANE

Good

Over: SALEM CANAL

2.0 N. 1.2 W. SUGAR CITY, Fremont, ID

Built 2017 Load: 31.8 t ADT: 130

ROAD

Good

Over: WARM RIVER

NO DATA ENTERED, Fremont, ID

Built 1980 Load: 31.8 t ADT: 36

SAVAGE PASS ROAD

Good

Over: BRIDGE CREEK

NO DATA ENTERED, Idaho, ID

Built 2008 Load: 31.8 t ADT: 40

US 93

Good

Over: 'M' CANAL

12.3 N. TWIN FALLS, Jerome, ID

Built 1984 Load: 31.8 t ADT: 6,500

N 2000 E

Good

Over: N.FK.TETON RIVER

1.5 N. SUGAR CITY, Madison, ID

Built 1976 Load: 31.8 t ADT: 1,700

SILVER CK. SMT. RD

Good

Over: SILVER CREEK

EGGERS CREEK CABIN, Valley, ID

Built 2010 Load: 31.8 t ADT: 50

SILVER CK. SMT. RD

Good

Over: SILVER CREEK

SILVER CK SUMMIT T.H., Valley, ID

Built 2010 Load: 31.8 t ADT: 50

FDR 662

Good

Over: HUGHES FORK

NO DATA ENTERED, Bonner, ID

Built 2016 Load: 32.1 t ADT: 50

STC3840;2ND FORK

Good

Over: SQUAW CREEK

4.5 N. OLA, Gem, ID

Built 2016 Load: 32.1 t ADT: 230

FS ROUTE NO. 412

Good

Over: SHOSHONE CREEK

9 MI FROM SHOSHONE W.C., Shoshone, ID

Built 1977 Load: 32.1 t ADT: 50

MAIN STREET

Good

Over: OROFINO CREEK

IN OROFINO; MAIN ST, Clearwater, ID

Built 1984 Load: 32.4 t ADT: 500

S 2ND WEST STREET

Good

Over: EGIN CANAL

IN ST ANTHONY, Fremont, ID

Built 2020 Load: 32.4 t ADT: 250

FS ROUTE NO. 534

Good

Over: POTTER CREEK

POTTER CR ABOVE TRAIL CR, Kootenai, ID

Built 2010 Load: 32.4 t ADT: 40

FDR 447

Good

Over: PALOUSE RIVER

19 MILES FROM POTLATCH ID, Latah, ID

Built 2021 Load: 32.4 t ADT: 15

S3760;FLTG FEATHER

Good

Over: MIDDLETON CANAL

1.0 N. 0.2 E. STAR, Ada, ID

Built 1988 Load: 32.7 t ADT: 4,400

SMA9243;VICTORY RD

Good

Over: CALKINS LATERAL

2.5 S 1.9 W MERIDIAN, Ada, ID

Built 2016 Load: 32.7 t ADT: 3,800

STC9573:E MALLARD

Good

Over: LOGGERS CREEK

IN BOISE; E.MALLARD DRIVE, Ada, ID

Built 2023 Load: 32.7 t ADT: 2,600

STC7221;CARSON ST

Good

Over: PORTNEUF RIVER

IN POCATELLO;CARSON ST., Bannock, ID

Built 2023 Load: 32.7 t ADT: 4,500

ROAD

Good

Over: HYNDMAN CREEK

HINDMAN CREEK, Blaine, ID

Built 1994 Load: 32.7 t ADT: 80

NORTHWEST PASSAGE

Good

Over: SKI TRAIL

6.0 N. 3.5 W. SANDPOINT, Bonner, ID

Built 2023 Load: 32.7 t ADT: 100

S. 4TH AVENUE

Good

Over: INDIAN CREEK

IN CALDWELL; S 4TH AVE, Canyon, ID

Built 2023 Load: 32.7 t ADT: 470

STC2739;ROCK CR RD

Good

Over: ROCK CREEK

17.8 S. HANSON, Cassia, ID

Built 1971 Load: 32.7 t ADT: 590

E 200 N

Good

Over: SALEM UNION CANAL

3.7 S 3.6 W ST ANTHONY, Fremont, ID

Built 2023 Load: 32.7 t ADT: 500

SPUR 653C

Good

Over: SEC.FK.CHIEF EAGLE EYE

2 MI NW SAGEHEN RSRVOIR, Gem, ID

Built 1980 Load: 32.7 t ADT: 15

1700 SOUTH ROAD

Good

Over: BIG WOOD RIVER

1.0 N. 1.6 W. GOODING, Gooding, ID

Built 2023 Load: 32.7 t ADT: 280

S 1800 E

Good

Over: LITTLE WOOD RIVER

0.4 S. 1.0 W. GOODING, Gooding, ID

Built 2023 Load: 32.7 t ADT: 1,300

FRD 5956

Good

Over: PACK CREEK

1 MILE EAST OF LOLO PASS, Idaho, ID

Built 2012 Load: 32.7 t ADT: 10

I 90 EBL

Good

Over: I 90 EB ON RAMP

POST FALLS ECL, Kootenai, ID

Built 2023 Load: 32.7 t ADT: 32,250

NO DATA ENTERED

Good

Over: BLACKBIRD CREEK

NO DATA ENTERED, Lemhi, ID

Built 1973 Load: 32.7 t ADT: 50

ARKOOSH ROAD

Good

Over: LITTLE WOOD RIVER

1.3 N 8.4 W. SHOSHONE, Lincoln, ID

Built 2023 Load: 32.7 t ADT: 30

FLINT CREEK ROAD

Good

Over: N.FK.BOULDER CREEK

29.0 W. OREANA, Owyhee, ID

Built 2023 Load: 32.7 t ADT: 30

4200 NORTH ROAD

Good

Over: DEEP CREEK

0.6 N. 4.4 W. BUHL, Twin Falls, ID

Built 2023 Load: 32.7 t ADT: 132

PARK CK. C.G. RD.

Good

Over: CLEAR CREEK

3 MI N.E. OF LOWMAN, ID, Boise, ID

Built 1957 Load: 33.0 t ADT: 25

R0AD

Good

Over: DEER CREEK

NO DATA ENTERED, Boundary, ID

Built 2015 Load: 33.0 t ADT: 40

NO DATA ENTERED

Good

Over: WAW'AALAMNINE CREEK

JUNCTION RD 108 & 5613, Idaho, ID

Built 1978 Load: 33.0 t ADT: 30

HOOPER LANE

Good

Over: BIG SPRINGS CONN. DITCH

2.9 S 0.8 E MAY, Lemhi, ID

Built 2011 Load: 33.0 t ADT: 70

NO DATA ENTERED

Good

Over: LITTLE NF CLEARWATER

NO DATA ENTERED, Shoshone, ID

Built 2014 Load: 33.0 t ADT: 40

FS ROUTE NO. 278

Good

Over: JOHNSON CREEK

JOHNSON CREEK, Bonner, ID

Built 2022 Load: 33.4 t ADT: 50

I 84 EBL

Good

Over: PHYLLIS CANAL

IN NAMPA, Canyon, ID

Built 2012 Load: 33.4 t ADT: 52,750

STC6870;PAHSIMEROI

Good

Over: BIG CREEK FISH PASSAGE

9.0 S. 10.4 E. MAY, Custer, ID

Built 2014 Load: 33.4 t ADT: 30

E 400 N

Good

Over: CROSSCUT CANAL

4.0 N 0.7 W NEWDALE, Fremont, ID

Built 2013 Load: 33.4 t ADT: 250

NO DATA ENTERED

Good

Over: NO DATA ENTERED

NO DATA ENTERED, Shoshone, ID

Built 2015 Load: 33.4 t ADT: 40

BASELINE ROAD

Good

Over: WILLOW CREEK

2.1 N. 11.5 E. FAIRFIELD, Camas, ID

Built 1989 Load: 33.6 t ADT: 170

BASELINE ROAD

Good

Over: 'C-2' CANAL

1.0 N. 0.8 W. PAUL, Minidoka, ID

Built 1999 Load: 33.6 t ADT: 150

Showing 1,301-1,350 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.