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

SUMMIT FLAT ROAD

Good

Over: GRIMES CREEK

5 MI SW OF PINE FLATS CG, Boise, ID

Built 1982 Load: 33.7 t ADT: 12

NO DATA ENTERED

Good

Over: ELIZABETH CREEK

7 MI N OF KELLY FORKS WC, Clearwater, ID

Built 1954 Load: 33.7 t ADT: 80

NO DATA ENTERED

Good

Over: HIDDEN CREEK

12 MI FROM KELLY FORKS WC, Clearwater, ID

Built 2010 Load: 33.7 t ADT: 50

FDR

Good

Over: REDFISH LAKE CREEK

REDFISH LAKE OUTLET, Custer, ID

Built 2015 Load: 33.7 t ADT: 500

N2100E

Good

Over: CONSOLIDATED FARMERS CNL

2.7 W 2.5 S ST ANTHONY, Fremont, ID

Built 2014 Load: 33.7 t ADT: 140

N 3900 E; IONA RD

Good

Over: BURGESS CNL; SW RIGBY BR

0.5 S 0.4 W RIGBY, Jefferson, ID

Built 2013 Load: 33.7 t ADT: 3,000

WILLIAMS CREEK RD

Good

Over: SALMON RIVER; SHOUP BR

5.4 S. SALMON, Lemhi, ID

Built 2018 Load: 33.7 t ADT: 1,100

3236: RIVERWOOD RO

Good

Over: Little Wood River

0.5 mi S of US26, Lincoln, ID

Built 1999 Load: 33.7 t ADT: 25

FS ROUTE NO. 933

Good

Over: BEAVER CREEK

.01 MI FROM COUNTY RD 456, Shoshone, ID

Built 1985 Load: 33.7 t ADT: 50

FS ROUTE NO. 326

Good

Over: CLIFF CREEK

CLIFF CREEK, Shoshone, ID

Built 2010 Load: 33.7 t ADT: 40

SH 6

Good

Over: SANTA CREEK; N. EMIDA BR

2.2 N. 2.7 E. EMIDA, Benewah, ID

Built 2020 Load: 34.0 t ADT: 710

FDR 103

Good

Over: MIDDLE CREEK

24 MI NORTH OF FDR 100, Idaho, ID

Built 1973 Load: 34.0 t ADT: 5

N 5050 E

Good

Over: GREAT FEEDER CANAL HEAD

0.7 S. 0.4 W. HEISE, Jefferson, ID

Built 2016 Load: 34.0 t ADT: 40

FS ROUTE 612

Good

Over: N.F. CDA RIVER

18 MI FROM CD'A IDAHO, Kootenai, ID

Built 1976 Load: 34.0 t ADT: 40

BACK ROAD

Good

Over: WIMPEY CREEK

10.4 SE SALMON, Lemhi, ID

Built 2013 Load: 34.0 t ADT: 50

ESTHER SIMPLOT PK

Good

Over: ESTHERS POND

IN ESTHER SIMPLOT PARK, Ada, ID

Built 2016 Load: 34.3 t ADT: 80

GYPSY BAY ROAD

Good

Over: GYPSY CREEK

2.8 N. 7.7 W. SAGLE, Bonner, ID

Built 2020 Load: 34.3 t ADT: 30

NO DATA ENTERED

Good

Over: WYLIE CREEK

NO DATA ENTERED, Bonner, ID

Built 2014 Load: 34.3 t ADT: 40

STC5907;DEEP CRK

Good

Over: DEEP CREEK

1.5 N 0.3 W NAPLES, Boundary, ID

Built 2014 Load: 34.3 t ADT: 360

FOREST ROAD 440A

Good

Over: WEST FORK NEWSOME CREEK

NEWSOME CREEK DRAINAGE, Idaho, ID

Built 2019 Load: 34.3 t ADT: 50

SH 55

Good

Over: BOISE RIVER;N.CHANNEL

0.7 S. EAGLE, Ada, ID

Built 1978 Load: 34.5 t ADT: 40,500

FARNER ROAD

Good

Over: MORA CANAL

3.5 S. 6.6 W. NAMPA, Canyon, ID

Built 2003 Load: 34.5 t ADT: 50

3000 EAST ROAD

Good

Over: BADGER CREEK

3.3 N TETONIA, Teton, ID

Built 2013 Load: 34.5 t ADT: 100

NFSR 347

Good

Over: GRAYBACK GULCH

2.5 MI SW OF IDAHO CITY, Boise, ID

Built 2018 Load: 35.0 t ADT: 50

STC5907;DEEP CREEK

Good

Over: DEEP CREEK #4

4.1 N 0.3 E. NAPLES, Boundary, ID

Built 2012 Load: 35.0 t ADT: 360

NO DATA ENTERED

Good

Over: HAZARD CREEK

NO DATA ENTERED, Idaho, ID

Built 1965 Load: 35.0 t ADT: 50

ROAD

Good

Over: TWIN CREEK

WEST OF TWIN CR. C.G., Lemhi, ID

Built 2007 Load: 35.0 t ADT: 10

60036

Good

Over: INDIAN CREEK

NO DATA ENTERED, Lemhi, ID

Built 2008 Load: 35.0 t ADT: 5

MCGARY GRADE ROAD

Good

Over: POTLACH RIVER

0.8 N. 1.0 E. JULIAETTA, Nez Perce, ID

Built 2016 Load: 35.0 t ADT: 110

WHITEHAWK L.O. RD.

Good

Over: BEAR VALLEY CREEK

5 MI E. DEADWOOD RSRVOIR, Valley, ID

Built 1969 Load: 35.0 t ADT: 12

STC 1775;TURNER RD

Good

Over: PACIFICORP PENSTOCK

0.1 W GRACE, Caribou, ID

Built 2016 Load: 35.3 t ADT: 510

HOOPER LANE

Good

Over: LITTLE SPRINGS

3.0 S 0.8 E MAY, Lemhi, ID

Built 2011 Load: 35.3 t ADT: 70

AGENCY CREEK ROAD

Good

Over: AGENCY CREEK (BRIDGE 1)

0.5 E 0.5 S TENDOY, Lemhi, ID

Built 2016 Load: 35.3 t ADT: 30

US 95

Good

Over: ROCK CREEK

6.3 N. 1.0 E. WINCHESTER, Nez Perce, ID

Built 2022 Load: 35.3 t ADT: 3,800

FS ROUTE NO. 208

Good

Over: CDA RIVER

21 MI. FROM BABINS JCT., Shoshone, ID

Built 1965 Load: 35.3 t ADT: 40

US 89

Good

Over: MONTPELIER CK;UPPER NRWS

4.3 E MONTPELIER, Bear Lake, ID

Built 2008 Load: 35.4 t ADT: 1,300

FREEGOLD ROAD

Good

Over: SOLDIER CREEK

8.1 N 1.0 W. FAIRFIELD, Camas, ID

Built 2018 Load: 35.4 t ADT: 10

SABIN ROAD

Good

Over: FARMERS COOP SEBREE CNL

2.7 E. PARMA, Canyon, ID

Built 1985 Load: 35.4 t ADT: 90

S 400 W

Good

Over: G CANAL

4.0 W 0.7 S BURLEY, Cassia, ID

Built 1994 Load: 35.4 t ADT: 990

500 WEST ROAD

Good

Over: 'C' CANAL

0.7 N. 1.0 E. PAUL, Minidoka, ID

Built 2001 Load: 35.4 t ADT: 100

RIDGE ROAD

Good

Over: W.FK.WEISER RIVER

6.2 N. 1.1 W. COUNCIL, Adams, ID

Built 2022 Load: 35.6 t ADT: 70

Adams Boulevard

Good

Over: Adams Drainage

9.3S. 13.5 E. Arco, Butte, ID

Built 1993 Load: 35.6 t ADT: 491

NO DATA ENTERED

Good

Over: DEEP CR

NO DATA ENTERED, Idaho, ID

Built 2018 Load: 35.6 t ADT: 5

FUREY LANE

Good

Over: PAHSIMEROI RIVER

5.0 W PATTERSON, Lemhi, ID

Built 2015 Load: 35.6 t ADT: 90

3309: MARKET LAKE

Good

Over: Market Lake Canel

.2 mi SW of Twin Butte Rd, Madison, ID

Built 2000 Load: 35.6 t ADT: 25

SILVER CREEK ROAD

Good

Over: SILVER CREEK

7 MI W DEADWOOD RSRVOIR, Valley, ID

Built 1967 Load: 35.6 t ADT: 60

FS ROUTE NO. 280

Good

Over: NF GROUSE CREEK

NF GROUSE, Bonner, ID

Built 2011 Load: 36.0 t ADT: 40

Forest Road 277

Good

Over: South Fork of the Snake

PALISADES DAM, Bonneville, ID

Built 2012 Load: 36.0 t ADT: 100

I 84 WBL

Good

Over: NEW YORK CANAL

IN BOISE;NEAR ORCHARD ST., Ada, ID

Built 1968 Load: 36.3 t ADT: 44,500

PIONEER ROAD

Good

Over: SHAFER CREEK

1.0S 0.1W HORSESHOE BEND, Boise, ID

Built 1988 Load: 36.3 t ADT: 280

Showing 1,351-1,400 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.