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

NO DATA ENTERED

Fair

Over: PANTHER CREEK

5.2 MILES SW OF COBALT, Lemhi, ID

Built 1953 Load: 22.4 t ADT: 50

STC 5786;COLBURN

Fair

Over: PACK RIVER

10.3 NE. SANDPOINT, Bonner, ID

Built 1951 Load: 22.5 t ADT: 1,300

NO DATA ENTERED

Fair

Over: JOHNSON CREEK

NO DATA ENTERED, Adams, ID

Built 1970 Load: 22.7 t ADT: 50

STP 7391;S. MAIN

Fair

Over: PORTNEUF RIVER

2.0 S. POCATELLO, Bannock, ID

Built 1967 Load: 22.7 t ADT: 7,800

SMA 3824;BNKS LWMN

Fair

Over: DEADWOOD RIVER

22.1 E. CROUCH, Boise, ID

Built 1985 Load: 22.7 t ADT: 660

FS ROUTE NO. 628

Fair

Over: BOULDER CREEK

BOULDER CREEK, Boundary, ID

Built 1981 Load: 22.7 t ADT: 50

FDR 581

Fair

Over: CAYUSE CREEK

7 MI E OF OLD KELLY CR RS, Clearwater, ID

Built 1967 Load: 22.7 t ADT: 20

SH 21

Fair

Over: CROOKED CREEK

3.1 W. STANLEY, Custer, ID

Built 1968 Load: 22.7 t ADT: 1,800

BEAVER CREEK ROAD

Fair

Over: MARSH CREEK

CROSSES MARSH CREEK, Custer, ID

Built 1964 Load: 22.7 t ADT: 50

STC 6731;55TH EAST

Fair

Over: HARRISON CANAL

2.3 N. 2 E. UCON, Jefferson, ID

Built 1961 Load: 22.7 t ADT: 3,900

INDIAN CREEK RD

Fair

Over: INDIAN CREEK(#4)

22.0 NW SALMON, Lemhi, ID

Built 1970 Load: 22.7 t ADT: 15

FSR 60055

Fair

Over: PANTHER CREEK

2.4 MILES NNE OF COBALT, Lemhi, ID

Built 1963 Load: 22.7 t ADT: 50

3209: NORTH PAGARI

Fair

Over: Little Wood River

0.7 mi SE of US26, Lincoln, ID

Built 1980 Load: 22.7 t ADT: 25

S YELLOWSTONE HWY

Fair

Over: TEXAS SLOUGH

AT THORNTON, Madison, ID

Built 1938 Load: 22.7 t ADT: 120

FS ROUTE NO. 300A

Fair

Over: SQ___ CREEK

3.7 MILES FROM AVERY, ID, Shoshone, ID

Built 1938 Load: 22.7 t ADT: 50

NO DATA ENTERED

Fair

Over: LOLO CREEK

SECTION 6, Clearwater, ID

Built 1962 Load: 23.3 t ADT: 10

ADMIN. ROAD

Fair

Over: RED RIVER

RED RIVER R.S. COMPOUND, Idaho, ID

Built 1965 Load: 23.3 t ADT: 50

FDR 61000

Fair

Over: PANTHER CREEK

6.5 MILES SW OF COBALT, Lemhi, ID

Built 1983 Load: 23.3 t ADT: 50

ROAD

Fair

Over: MOOSE CREEK

NO DATA ENTERED, Teton, ID

Built 1975 Load: 23.3 t ADT: 24

N 1300 E RD(BYRNE)

Fair

Over: OWSLEY CANAL;S TERRETON

0.9 S. TERRETON, Jefferson, ID

Built 1976 Load: 23.4 t ADT: 40

DAM ROAD

Fair

Over: EAST CANAL

2.7 S. 1.5 W. OAKLEY, Cassia, ID

Built 2015 Load: 23.6 t ADT: 20

STC 3809;MIDDLE FK

Fair

Over: M.FK.BOISE R;SHEEP CREEK

3.0 NE TWIN SPRINGS, Elmore, ID

Built 1965 Load: 23.6 t ADT: 30

STC6764;W MAIN ST

Fair

Over: EGIN CANAL

IN ST ANTHONY;W.MAIN ST, Fremont, ID

Built 1986 Load: 23.6 t ADT: 1,100

N ELK LAKE RD

Fair

Over: ELK CREEK

13.9 S. 0.3 E. RIGGINS, Idaho, ID

Built 1965 Load: 23.6 t ADT: 50

STC 6768;N 4700 E

Fair

Over: FARMERS FRIEND CANAL

0.5 E. 0.7 N. RIRIE, Jefferson, ID

Built 1950 Load: 23.6 t ADT: 2,200

OLD HWY 8

Fair

Over: BIG BEAR CREEK

1.0 S. 1.8 W. DEARY, Latah, ID

Built 1940 Load: 23.6 t ADT: 30

US 95

Fair

Over: JUMP CREEK

5.0 S. HOMEDALE, Owyhee, ID

Built 1982 Load: 23.6 t ADT: 3,200

5750 SOUTH

Fair

Over: TETON RIVER(WHITE BR)

2.6 N. 3.2 W. VICTOR, Teton, ID

Built 1983 Load: 23.6 t ADT: 190

N 3700 E ROAD

Fair

Over: LOW LINE CANAL

3.1 S. 1.0 W. HANSEN, Twin Falls, ID

Built 1978 Load: 23.6 t ADT: 70

1900 EAST ROAD

Fair

Over: SALMON RIVER CANAL

4.7 S. 5.0 W. HOLLISTER, Twin Falls, ID

Built 1980 Load: 23.6 t ADT: 30

RDS

Fair

Over: LITTLE SMOKY CREEK

UPPER LITTLE SMOKY CREEK, Camas, ID

Built 1966 Load: 23.7 t ADT: 25

NO DATA ENTERED

Fair

Over: LOST CREEK

NO DATA ENTERED, Adams, ID

Built 1975 Load: 24.0 t ADT: 50

ST CHARLES RD

Fair

Over: ST CHARLES CREEK

NO DATA ENTERED, Bear Lake, ID

Built 1967 Load: 24.0 t ADT: 200

FDR

Fair

Over: NORTH FORK WOOD RIVER

3 MILES NORTH SNRA HQDS, Blaine, ID

Built 1955 Load: 24.0 t ADT: 50

FDR

Fair

Over: ALTURAS LAKE CREEK

2 MILES NORTH ALTURAS L., Blaine, ID

Built 1955 Load: 24.0 t ADT: 50

FS ROUTE NO. 312

Fair

Over: UPPER W. BRANCH

UPPER WEST BRANCH, Bonner, ID

Built 1954 Load: 24.0 t ADT: 50

TREALOR CREEK ROAD

Fair

Over: SQ___ CREEK

NO DATA ENTERED, Custer, ID

Built 1966 Load: 24.0 t ADT: 40

FDR

Fair

Over: FISHHOOK CREEK

REDFISH LAKE BEACH AREA, Custer, ID

Built 1956 Load: 24.0 t ADT: 50

FDR

Fair

Over: STANLEY LAKE CREEK

1/2 MILE EAST OF HWY 21, Custer, ID

Built 1969 Load: 24.0 t ADT: 50

GOTSCH ROAD

Fair

Over: 'D' LINE CANAL

0.7 N. 3.7 E. PARMA, Canyon, ID

Built 1974 Load: 24.3 t ADT: 100

SQ___ CREEK ROAD

Fair

Over: PAASASIKWANA NAOKWAIDE

NO DATA ENTERED, Custer, ID

Built 1964 Load: 24.3 t ADT: 20

FOREST ROAD 1800

Fair

Over: RED RIVER

NO DATA ENTERED, Idaho, ID

Built 1960 Load: 24.3 t ADT: 50

NORTH 4825 EAST

Fair

Over: ENTERPRISE CANAL

0.8 N. 1.8 E. RIRIE, Jefferson, ID

Built 1970 Load: 24.3 t ADT: 80

105TH EAST RD

Fair

Over: HARRISON CANAL

0.3 N. 2.4 W. RIRIE, Jefferson, ID

Built 1974 Load: 24.3 t ADT: 90

N 1800 E RD

Fair

Over: CAMAS CREEK

2.9 N. 5.0 E. TERRETON, Jefferson, ID

Built 1969 Load: 24.3 t ADT: 200

N 3600 E RD (HITT)

Fair

Over: DRY BED CR;NE.LEWISVILLE

0.9 N. 1.5 E. LEWISVILLE, Jefferson, ID

Built 1967 Load: 24.3 t ADT: 30

RAYS LAKE ROAD

Fair

Over: CAMAS CREEK

4.3 MI. SSW OF HDQTRS, Jefferson, ID

Built 1939 Load: 24.3 t ADT: 5

3708: DEEP CREEK

Fair

Over: North Fork Owyhee River

70.1 mi S of ID78, Owyhee, ID

Built 1968 Load: 24.3 t ADT: 25

IRR BIA RTE 68

Fair

Over: SPRING CREEK

16KM W.FT HALL IN BOTTOMS, Bannock, ID

Built 1975 Load: 24.5 t ADT: 60

100 WEST ST

Fair

Over: ST. CHARLES CR N. BRIDGE

IN CITY OF ST. CHARLES, Bear Lake, ID

Built 1920 Load: 24.5 t ADT: 50

Showing 451-500 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.