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 NO. 2636

Good

Over: TRAPPER CREEK

TRAPPER CREEK, Bonner, ID

Built 1973 Load: 24.0 t ADT: 50

NO DATA ENTERED

Good

Over: GOOSE CREEK

NO DATA ENTERED, Adams, ID

Built 1963 Load: 24.3 t ADT: 50

HUNTER CK-CRKD. R.

Good

Over: CROOKED RIVER

6.8 MI NNW OF DEER PARK, Boise, ID

Built 1963 Load: 24.3 t ADT: 12

FS ROUTE NO. 448

Good

Over: ROUND PRAIRIE CREEK

ROUND PRAIRIE CREEK, Boundary, ID

Built 1978 Load: 24.3 t ADT: 40

NO DATA ENTERED

Good

Over: SNAKE CR

NO DATA ENTERED, Idaho, ID

Built 1949 Load: 24.3 t ADT: 40

N 2900 E(HACKWART)

Good

Over: BUTTE MARKET LAKE CANAL

4.0 S. 0.2 E. ROBERTS, Jefferson, ID

Built 1975 Load: 24.3 t ADT: 30

FDR 381

Good

Over: PALOUSE RIVER

13 MILES FROM POTLATCH ID, Latah, ID

Built 1979 Load: 24.3 t ADT: 15

IRR BIA RTE 24

Good

Over: LITTLE HANGMAN CREEK

9.6 KM SW OF AGENCY, Benewah, ID

Built 1998 Load: 24.5 t ADT: 25

IRR BIA RTE 60

Good

Over: SPRING CREEK

7KM W.JCT HWY 191 & RT 60, Bingham, ID

Built 1975 Load: 24.5 t ADT: 150

IRR BIA RTE 8

Good

Over: BLACKFOOT RIVER

9 KM E OF HWY 191&BLKFOOT, Bingham, ID

Built 1975 Load: 24.5 t ADT: 210

IRR BIA RTE 24

Good

Over: MAIN CANAL

4 KM EAST OF FORT HALL, Bingham, ID

Built 1969 Load: 24.5 t ADT: 820

OLD ADDIE ROAD

Good

Over: MOYIE RIVER (ADDIE BR)

0.1 N. 0.7 E. ADDIE, Boundary, ID

Built 1991 Load: 24.5 t ADT: 90

REDROCK LOOP

Good

Over: LITTLE LOST RIVER

NO DATA ENTERED, Custer, ID

Built 1966 Load: 24.6 t ADT: 10

20097

Good

Over: WARM RIVER

NO DATA ENTERED, Fremont, ID

Built 2015 Load: 24.6 t ADT: 50

FRD 5671

Good

Over: PACK CREEK

10 MINS S OF LOLO PASS, Idaho, ID

Built 2012 Load: 24.9 t ADT: 10

FS ROUTE 2354

Good

Over: INK CREEK

NO DATA ENTERED, Shoshone, ID

Built 2010 Load: 24.9 t ADT: 40

SAND CREEK ROAD

Good

Over: SAND CREEK

2 MI E LANDMARK AIRSTRIP, Valley, ID

Built 1976 Load: 24.9 t ADT: 5

NORTH 4850 EAST RD

Good

Over: ANDERSON CANAL

0.1 N. 2.0 E. RIRIE, Jefferson, ID

Built 1974 Load: 25.2 t ADT: 20

N 2900 E RD

Good

Over: BUTTE MARKET LAKE CANAL

1.0 N. 0.2 E. ROBERTS, Jefferson, ID

Built 1974 Load: 25.2 t ADT: 30

N 3600 E RD

Good

Over: BURGESS CANAL

1.1 S. 3.4 W. RIGBY, Jefferson, ID

Built 1967 Load: 25.2 t ADT: 290

WAPITI ROAD

Good

Over: SOUTH FORK PAYETTE RIVER

WAPITI CR SUMMER HOME, Boise, ID

Built 1976 Load: 25.3 t ADT: 25

FS ROUTE NO. 2730

Good

Over: CONSULAS CREEK

CONSALUS CREEK, Bonner, ID

Built 2010 Load: 25.3 t ADT: 40

SMITH CK. SPUR E

Good

Over: SMITH CREEK

.1 MI. SO. RD. 175, Elmore, ID

Built 1986 Load: 25.3 t ADT: 5

3043: WARM SPRING

Good

Over: Big Timber Creek

5 mi W of ID28, Lemhi, ID

Built 1979 Load: 25.3 t ADT: 25

N 3980 EAST ROAD

Good

Over: DRY BED

1.8 N. 0.3 E. RIGBY, Jefferson, ID

Built 1992 Load: 25.4 t ADT: 100

FDR

Good

Over: BAKER CREEK

5 MILES UP BAKER CREEK, Blaine, ID

Built 1964 Load: 25.6 t ADT: 100

FS ROUTE NO. 633

Good

Over: PEAK CREEK

PEAK CREEK, Boundary, ID

Built 1955 Load: 25.6 t ADT: 40

DRY BUCK-BURNT CK.

Good

Over: EAST FORK FALL CREEK

1.8 MI W. OF RED MOUNTAIN, Elmore, ID

Built 2010 Load: 25.6 t ADT: 50

2502: LYONS BAR

Good

Over: White Bird Creek

0.5 mi W of US95, Idaho, ID

Built 2000 Load: 25.6 t ADT: 25

FS ROUTE NO. 760

Good

Over: LITTLE NF CLEARWATER

LITTLE NF CLEARWATER, Shoshone, ID

Built 2006 Load: 25.6 t ADT: 40

FS ROUTE NO. 812

Good

Over: BIG ELK CREEK

TEPEE CREEK, Shoshone, ID

Built 1952 Load: 25.6 t ADT: 40

ROADWAY

Good

Over: BRUSH CREEK

4 MI SSW OF LAKE CASCADE, Valley, ID

Built 1984 Load: 25.6 t ADT: 12

DEADWD. RESV. RD.

Good

Over: WILD BUCK CREEK

1 MI N DEADWOOD RESRVIOR, Valley, ID

Built 1975 Load: 25.6 t ADT: 12

STANLEY-WARM LAKE

Good

Over: FIR CREEK

2 MI E. OF BRUCE MEADOWS, Valley, ID

Built 2009 Load: 25.6 t ADT: 50

RAMMAGE MEADOWS RD

Good

Over: THIRD FK.CHIEF EAGLE EYE

THIRD FORK CABIN, Gem, ID

Built 1963 Load: 25.9 t ADT: 20

FOREST ROAD 1803

Good

Over: RED RIVER

2 MI. FROM ELK CITY, Idaho, ID

Built 1967 Load: 25.9 t ADT: 40

DEADWD. RESV. RD.

Good

Over: BASIN CREEK

.1 MI N DEADWOOD RESRVOIR, Valley, ID

Built 1975 Load: 25.9 t ADT: 12

MCCOY CREEK ROAD

Good

Over: MCCOY CREEK

NO DATA ENTERED, Bonneville, ID

Built 1986 Load: 26.2 t ADT: 36

LUNCH CK. FLAT RD.

Good

Over: LUNCH CREEK

2 MI NW LANDMARK AIRSTRIP, Valley, ID

Built 1980 Load: 26.2 t ADT: 5

W. CAMAS CREEK RD

Good

Over: BEAVER CREEK

3.42 N SPENCER, Clark, ID

Built 1970 Load: 26.3 t ADT: 110

CHALLIS CREEK RD

Good

Over: CHALLIS CREEK

3.8 N. 1.8 W. CHALLIS, Custer, ID

Built 1997 Load: 26.3 t ADT: 470

CROOKED RIVER ROAD

Good

Over: CROOKED RIVER

6.0 S. 4.0 W. ELK CITY, Idaho, ID

Built 1965 Load: 26.3 t ADT: 110

100 SOUTH ROAD

Good

Over: 'N' CANAL

1.0 S. 0.8 W. JEROME, Jerome, ID

Built 1995 Load: 26.3 t ADT: 1,300

ROAD

Good

Over: ROCK CREEK

NO DATA ENTERED, Fremont, ID

Built 1980 Load: 26.6 t ADT: 50

NO DATA ENTERED

Good

Over: LOLO CREEK

WHITE CREEK, Idaho, ID

Built 1987 Load: 26.6 t ADT: 150

FDR 568

Good

Over: EAST FORK LEGENDARY BEAR

RD. 568 MP 3.20, Idaho, ID

Built 2003 Load: 26.6 t ADT: 5

NO DATA ENTERED

Good

Over: MANN CREEK

NO DATA ENTERED, Washington, ID

Built 1976 Load: 26.6 t ADT: 50

1920: DARLING CREE

Good

Over: West Fork Morgan Creek

6.5 mi NW of US93, Custer, ID

Built 1995 Load: 26.9 t ADT: 25

ROUGH CREEK ROAD

Good

Over: MORES CREEK

8.5 MI NE IDAHO CITY, Boise, ID

Built 1979 Load: 27.2 t ADT: 25

FS ROUTE NO. 1347

Good

Over: FEDAR CREEK

FEDAR CREEK, Bonner, ID

Built 2010 Load: 27.2 t ADT: 40

Showing 1,151-1,200 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.