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

IRR BIA RTE 187

Fair

Over: BANNOCK CREEK

.4K N&.8 K W.OF 161 & I15, Power, ID

Built 1971 Load: 40.1 t ADT: 55

FOREST ROAD 443

Fair

Over: AMERICAN RIVER

4 MILES NORTH OF ELK CITY, Idaho, ID

Built 1965 Load: 40.2 t ADT: 50

FS ROUTE NO. 208

Fair

Over: CINNAMON CREEK

23.6 MI FROM BABINS JCT., Shoshone, ID

Built 1974 Load: 40.2 t ADT: 40

FS ROUTE NO. 437

Fair

Over: N.F. HAYDEN CR

NF HAYDEN CREEK, Kootenai, ID

Built 1953 Load: 40.5 t ADT: 50

NO DATA ENTERED

Fair

Over: E FK WEISER R

NO DATA ENTERED, Adams, ID

Built 1966 Load: 40.8 t ADT: 50

US 95

Fair

Over: MOYIE R; UPPER EASTPORT

0.1 S. EASTPORT (CANADA), Boundary, ID

Built 2005 Load: 40.8 t ADT: 550

BATT CORNER ROAD

Fair

Over: RIVERSIDE CANAL

3.7 S. 1.3 E. PARMA, Canyon, ID

Built 1997 Load: 40.8 t ADT: 400

CHISHOLM DRIVE

Fair

Over: PHYLLIS CANAL

1.4 N. 0.2 E. NAMPA, Canyon, ID

Built 1996 Load: 40.8 t ADT: 5

I 84 EBL

Fair

Over: MAIN NORTHSIDE CANAL

13.9 W. BURLEY, Jerome, ID

Built 1966 Load: 40.8 t ADT: 11,750

US 95

Fair

Over: NPRR;CLEARWATER RIVER

4 N. LAPWAI, Nez Perce, ID

Built 1962 Load: 40.8 t ADT: 6,200

FS ROUTE NO. 301

Fair

Over: GOLD CENTER CR

5.3 MILES FROM CLARKIA, Shoshone, ID

Built 1986 Load: 40.8 t ADT: 40

SH 50

Fair

Over: SNAKE RIVER;HANSEN BR.

8.3 E. TWIN FALLS, Twin Falls, ID

Built 1966 Load: 40.8 t ADT: 8,700

US 95

Fair

Over: WEISER RIVER

0.2 N. CAMBRIDGE SECL, Washington, ID

Built 1954 Load: 40.8 t ADT: 3,100

FDR 711

Fair

Over: QUARTZ CREEK

48 MILES FROM PIERCE ID, Clearwater, ID

Built 1967 Load: 41.1 t ADT: 5

FS ROUTE NO. 208

Fair

Over: CDA RIVER

14.8 MI FROM BABINS JCT., Shoshone, ID

Built 1967 Load: 41.1 t ADT: 40

FS ROUTE NO. 1268

Fair

Over: ADAIR CREEK

ADAIR CREEK, Shoshone, ID

Built 1969 Load: 41.5 t ADT: 50

STP7243;E PARK CTR

Fair

Over: BOISE RIVER

EAST BOISE, Ada, ID

Built 2009 Load: 41.7 t ADT: 9,600

BRENTWOOD DRIVE

Fair

Over: EAST LATERAL CANAL

IN IDAHO FALLS, Bonneville, ID

Built 1975 Load: 41.7 t ADT: 1,000

STC2863;600 WEST R

Fair

Over: 'C' CANAL

0.6 N. PAUL;040S-600W, Minidoka, ID

Built 1979 Load: 41.7 t ADT: 3,400

FDR 712

Fair

Over: QUARTZ CREEK

50 MILES FROM PIERCE ID, Clearwater, ID

Built 1967 Load: 41.8 t ADT: 20

FOREST ROAD 222-D

Fair

Over: CROOKED CREEK

DIXIE, ID, Idaho, ID

Built 1959 Load: 41.8 t ADT: 10

FS ROUTE NO. 338

Fair

Over: BIRD CREEK

BIRD CREEK, Shoshone, ID

Built 1956 Load: 41.8 t ADT: 50

US 95

Fair

Over: LAPWAI CREEK

1.0 S. CULDESAC, Nez Perce, ID

Built 2012 Load: 42.1 t ADT: 3,500

COUNTY RD; FR 754

Fair

Over: ST JOE RIVER;ST JOE BR

1.0 N. 10.0 E. ST MARIES, Benewah, ID

Built 1979 Load: 42.3 t ADT: 230

STC 9623;W. WRIGHT

Fair

Over: NEW YORK CANAL

IN BOISE;W.WRIGHT ST, Ada, ID

Built 1989 Load: 42.6 t ADT: 6,200

US 91

Fair

Over: BEAR RIVER

2.2 N. PRESTON, Franklin, ID

Built 2006 Load: 42.6 t ADT: 4,200

E 3RD N; SALEM CH

Fair

Over: SALEM CANAL

IN SUGAR CITY;3RD N.ST, Madison, ID

Built 1978 Load: 42.6 t ADT: 260

STC2730;3000 E. RD

Fair

Over: LOW LINE CANAL

3S.TWIN FALLS;3500N-3000E, Twin Falls, ID

Built 1964 Load: 42.6 t ADT: 1,400

2508: PARTRIDGE CR

Fair

Over: PARTRIDGE CREEK

Travel East on Big Salmon, Idaho, ID

Built 1990 Load: 42.8 t ADT: 4

FDR

Fair

Over: HELL ROARING CREEK

2 MILES WEST SVWC, Custer, ID

Built 1984 Load: 43.1 t ADT: 50

BEAVER-LOON ROAD

Fair

Over: JORDAN CREEK

NO DATA ENTERED, Custer, ID

Built 2001 Load: 43.4 t ADT: 100

MIDDLE FORK ROAD

Fair

Over: M.FK.WEISER RIVER

9.3 W 5.2 S DONNELLY, Adams, ID

Built 1960 Load: 43.5 t ADT: 70

STERLING NORTH RD

Fair

Over: ABERDEEN SPRINGFIELD CNL

0.4 N. 2.5 W. SPRINGFIELD, Bingham, ID

Built 1982 Load: 43.5 t ADT: 40

US 20

Fair

Over: W.FK.SOLDIER CREEK

0.1 W. FAIRFIELD, Camas, ID

Built 1958 Load: 43.5 t ADT: 1,800

S6746;MENAN-LORENZ

Fair

Over: ISLAND CANAL

3.9 N 1.6 E RIGBY, Jefferson, ID

Built 2011 Load: 43.5 t ADT: 2,700

US 95

Fair

Over: COUGAR CREEK

4.1 S. COEUR D'ALENE, Kootenai, ID

Built 1985 Load: 43.5 t ADT: 10,000

300 SOUTH ROAD

Fair

Over: 'A' CANAL

1.6 N. 5.2 E. HEYBURN, Minidoka, ID

Built 2004 Load: 43.5 t ADT: 210

FDR 247

Fair

Over: SKULL CREEK

MILE PT 30.2- RD 247, Clearwater, ID

Built 1967 Load: 43.7 t ADT: 120

FDR 737

Fair

Over: LAKE CREEK

70 MI. FROM PIERCE, ID, Clearwater, ID

Built 1985 Load: 43.7 t ADT: 10

SH 55

Fair

Over: DRY CREEK

8.1 NW BOISE WCL, Ada, ID

Built 1997 Load: 44.5 t ADT: 13,500

PERO ROAD

Fair

Over: BELLEVUE CANAL

4.6 S. 1.6 E. BELLEVUE, Blaine, ID

Built 1993 Load: 44.5 t ADT: 100

US 95

Fair

Over: DEEP CR;BNRR;UPRR;NAPLES

0.4 S. NAPLES, Boundary, ID

Built 1965 Load: 44.5 t ADT: 7,000

SH 162

Fair

Over: LAWYERS CANYON CREEK

1.6 S KAMIAH, Idaho, ID

Built 2002 Load: 44.5 t ADT: 1,100

US 95 SBL

Fair

Over: N.FK. ROCK CREEK

3.6 N. WORLEY, Kootenai, ID

Built 2008 Load: 44.5 t ADT: 3,050

OLD HORNET ROAD

Fair

Over: HORNET CREEK

1.2 N. 2.2 W. COUNCIL, Adams, ID

Built 1971 Load: 45.4 t ADT: 100

US 89

Fair

Over: BEAR LAKE CANAL

2.7 W. MONTPELIER, Bear Lake, ID

Built 1973 Load: 45.4 t ADT: 3,000

STC 4718;SELWAY RD

Fair

Over: LOCHSA RIVER(LOWELL BR)

0.1 N. 18.2 E. KOOSKIA, Idaho, ID

Built 1960 Load: 45.4 t ADT: 180

I 90 WBL

Fair

Over: S.FK.COEUR D'ALENE RIVER

2.8 W. WALLACE, Shoshone, ID

Built 1978 Load: 45.4 t ADT: 5,750

FS ROUTE NO. 151

Fair

Over: FALLS CREEK

FALLS CREEK, Shoshone, ID

Built 1974 Load: 45.4 t ADT: 40

FS ROUTE NO. 320

Fair

Over: RED IVES CREEK

RED IVES CREEK, Shoshone, ID

Built 1964 Load: 45.4 t ADT: 50

Showing 951-1,000 of 1,742 bridges

Related

All states → | National rankings → | Understanding conditions → | SD bridges explained →
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.