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

FOREST ROAD 421

Fair

Over: MALLARD CREEK

NO DATA ENTERED, Idaho, ID

Built 1992 Load: 29.2 t ADT: 50

FOREST ROAD 223

Fair

Over: GEDNEY CR

18 MI. FROM LOWELL, ID, Idaho, ID

Built 1934 Load: 29.2 t ADT: 50

FS ROUTE NO. 311

Fair

Over: GRANITE CREEK

FORKS OF GRANITE, Bonner, ID

Built 1952 Load: 29.5 t ADT: 40

FS ROUTE NO. 1013

Fair

Over: LIME CREEK

LIME CREEK, Boundary, ID

Built 1964 Load: 29.5 t ADT: 40

FDR 1649

Fair

Over: LOCHSA RIVER

WLD GATEWAY CAMPGROUND, Idaho, ID

Built 1967 Load: 29.5 t ADT: 30

FOREST ROAD 1190

Fair

Over: TRAPPER CR

NO DATA ENTERED, Idaho, ID

Built 1958 Load: 29.5 t ADT: 40

FS ROUTE NO. 413

Fair

Over: COPPER CREEK

COPPER CREEK, Kootenai, ID

Built 1975 Load: 29.5 t ADT: 50

FS ROUTE NO. 442

Fair

Over: LOST CREEK

0.5 MI. FROM FH 208 JCT., Shoshone, ID

Built 1953 Load: 29.5 t ADT: 50

FS ROUTE NO. 321

Fair

Over: MARBLE CREEK

MARBLE CREEK, Shoshone, ID

Built 1952 Load: 29.5 t ADT: 50

E 100 N

Fair

Over: TETON CANAL

0.9 N. 1.2 E. TETON, Fremont, ID

Built 1980 Load: 29.7 t ADT: 180

NO DATA ENTERED

Fair

Over: LITTLE WEISER

NO DATA ENTERED, Adams, ID

Built 1953 Load: 29.8 t ADT: 50

FDR 373

Fair

Over: BRUSHY FORK

33 MILES EA OF POWELL R S, Idaho, ID

Built 1957 Load: 29.8 t ADT: 40

FOREST ROAD 651

Fair

Over: O'HARA CREEK

NO DATA ENTERED, Idaho, ID

Built 1958 Load: 29.8 t ADT: 50

FS ROUTE NO. 437

Fair

Over: HAYDEN CREEK

HAYDEN CREEK, Kootenai, ID

Built 1953 Load: 29.8 t ADT: 50

FS ROUTE NO. 919

Fair

Over: S. LAVERNE CR

SOUTH LAVERNE CREEK, Kootenai, ID

Built 1973 Load: 29.8 t ADT: 50

FS ROUTE NO. 490

Fair

Over: BOULDER CREEK

BOULDER CREEK, Shoshone, ID

Built 1965 Load: 29.8 t ADT: 40

LTTL WEISER RVR RD

Fair

Over: LITTLE WEISER RIVER

4.7S 2.2E INDIAN VALLEY, Adams, ID

Built 1953 Load: 29.9 t ADT: 30

I 15 NBL

Fair

Over: RAPID CREEK;INKOM

0.1 E. INKOM, Bannock, ID

Built 1963 Load: 29.9 t ADT: 7,750

STP 7151;N MAIN ST

Fair

Over: PORTNEUF RIVER

IN POCATELLO;MAIN ARTHUR, Bannock, ID

Built 1957 Load: 29.9 t ADT: 9,500

RAILROAD GRADE RD

Fair

Over: JACOT CREEK

4.7 E. ST. MARIES, Benewah, ID

Built 1912 Load: 29.9 t ADT: 40

KIMBALL RD;N 400 E

Fair

Over: SAND CREEK CANAL

2.5 S. KIMBALL, Bingham, ID

Built 1979 Load: 29.9 t ADT: 110

2900 WEST

Fair

Over: BIG LOST RIVER

3.5 S. 1.2 E. ARCO, Butte, ID

Built 1978 Load: 29.9 t ADT: 50

W ANTELOPE;FR 137

Fair

Over: ANTELOPE CREEK

20.8 W. 0.5 S. ARCO, Butte, ID

Built 1966 Load: 29.9 t ADT: 10

I 84

Fair

Over: FARMERS SEBREE CANAL

IN CALDWELL, Canyon, ID

Built 1980 Load: 29.9 t ADT: 51,000

US 95

Fair

Over: RIVERSIDE CANAL

4 N. WILDER, Canyon, ID

Built 1964 Load: 29.9 t ADT: 3,900

OLD FORT BOISE RD.

Fair

Over: 'D' LINE CANAL

2.4 N. 0.3 E. PARMA, Canyon, ID

Built 1984 Load: 29.9 t ADT: 90

SHENTON RD

Fair

Over: MEDICINE LODGE CR

6.6 W 0.5 N. DUBOIS, Clark, ID

Built 2007 Load: 29.9 t ADT: 10

WARDWELL STREET

Fair

Over: FARMERS COOP CANAL

IN EMMETT;WARDWELL ST, Gem, ID

Built 1990 Load: 29.9 t ADT: 400

1800 EAST ROAD

Fair

Over: BIG WOOD RIVER

0.7 N. 1.0 W. GOODING, Gooding, ID

Built 1958 Load: 29.9 t ADT: 660

STC6731;W 145 N

Fair

Over: IDAHO CANAL

9.3 N. 0.9 W. IDAHO FALLS, Jefferson, ID

Built 1967 Load: 29.9 t ADT: 2,600

SH 33

Fair

Over: HENRY'S FK.SNAKE RIVER

4.5 W. REXBURG, Madison, ID

Built 1977 Load: 29.9 t ADT: 3,000

SH 167

Fair

Over: SNAKE RIVER;GRANDVIEW BR

0.8 N. GRANDVIEW, Owyhee, ID

Built 1970 Load: 29.9 t ADT: 1,500

SH 33

Fair

Over: S.FK.LEIGH CREEK

2.8 S. TETONIA, Teton, ID

Built 1979 Load: 29.9 t ADT: 5,500

WEISER RIVER ROAD

Fair

Over: CRANE CREEK

3.1 N. 9.4 E. WEISER, Washington, ID

Built 1982 Load: 29.9 t ADT: 20

FS ROUTE NO. 1399

Fair

Over: HUGHES FORK CR

HUGHES FORK CREEK, Bonner, ID

Built 1966 Load: 30.1 t ADT: 50

FOREST ROAD 440A

Fair

Over: NEWSOME CREEK

NEWSOME CREEK, Idaho, ID

Built 1959 Load: 30.1 t ADT: 40

NO DATA ENTERED

Fair

Over: UPPER WEST BRANCH

UPPER WEST BRANCH, Bonner, ID

Built 1989 Load: 30.5 t ADT: 50

FDR 295

Fair

Over: GOOSE CREEK

30 MI SW OF SUPERIOR MT, Clearwater, ID

Built 1956 Load: 30.5 t ADT: 30

FDR 566

Fair

Over: FISHING CREEK

16 MILES TO POWELL R S, Idaho, ID

Built 1954 Load: 30.5 t ADT: 30

FS ROUTE NO. 412

Fair

Over: FALLS CREEK

NO DATA ENTERED, Shoshone, ID

Built 1975 Load: 30.5 t ADT: 50

FS ROUTE NO. 805

Fair

Over: WEST FORK EAGLE CREEK

W FK EAGLE CREEK, Shoshone, ID

Built 1957 Load: 30.5 t ADT: 50

FS ROUTE NO. 6924

Fair

Over: LOWER FLAT CR

LOWER FLAT CREEK, Shoshone, ID

Built 1981 Load: 30.5 t ADT: 50

SMOKY CANYON ROAD

Fair

Over: STUMP CREEK

13.7 S. 1.1 W. FREEDOM, Caribou, ID

Built 1982 Load: 30.6 t ADT: 30

STC 3770;STAR RD

Fair

Over: BOISE RIVER(STAR BRIDGE)

0.8 S. STAR, Ada, ID

Built 1982 Load: 30.8 t ADT: 11,000

STATE SHED ROAD

Fair

Over: W.BR.GOOSE CREEK

0.2 N. 0.1 E. NEW MEADOWS, Adams, ID

Built 1955 Load: 30.8 t ADT: 210

I 15 NBL

Fair

Over: GIBSON CANAL

5.5 S. BLACKFOOT, Bingham, ID

Built 1959 Load: 30.8 t ADT: 13,750

STC1837;W RIVER RD

Fair

Over: PEOPLES CANAL

5.6 N. 2.3 E. BLACKFOOT, Bingham, ID

Built 1954 Load: 30.8 t ADT: 1,300

US 20

Fair

Over: GROVE CREEK

12.1 W. CAREY, Blaine, ID

Built 1971 Load: 30.8 t ADT: 1,800

STC 5783;PENINSULA

Fair

Over: LOWER WEST BR. PRIEST R.

3.2N. 0.3E. PRIEST RIVER, Bonner, ID

Built 1975 Load: 30.8 t ADT: 750

STC 5804;WESTSIDE

Fair

Over: BALL CREEK

6.7N. 4.7W. BONNERS FERRY, Boundary, ID

Built 1990 Load: 30.8 t ADT: 300

Showing 701-750 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.