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

COPPER BASIN LOOP

Fair

Over: STAR HOPE CREEK

21.0 E. SUN VALLEY, Custer, ID

Built 1970 Load: 27.2 t ADT: 20

BEAVER-LOON ROAD

Fair

Over: W.FK MAYFIELD CREEK

19 MILES N OF SUNBEAM, Custer, ID

Built 1968 Load: 27.2 t ADT: 10

STC3830;IDAHO BLVD

Fair

Over: PAYETTE RIVER;E.LETHA BR

1.0 E. LETHA, Gem, ID

Built 1960 Load: 27.2 t ADT: 1,400

STC3842;OLD FRZOUT

Fair

Over: BLACK CANYON CANAL

2.7 S. 0.8 E. EMMETT, Gem, ID

Built 1950 Load: 27.2 t ADT: 330

FOREST ROAD 309

Fair

Over: MILL CREEK

1 MI. FROM STATE HWY 14, Idaho, ID

Built 1966 Load: 27.2 t ADT: 30

SH 48

Fair

Over: SNAKE RIVER DRY BED

0.5 N. LEWISVILLE, Jefferson, ID

Built 1980 Load: 27.2 t ADT: 1,800

FS ROUTE NO. 413

Fair

Over: COPPER CREEK

COPPER CREEK, Kootenai, ID

Built 1975 Load: 27.2 t ADT: 50

O'REILLY ROAD

Fair

Over: PALOUSE RIVER

1.7 W. HARVARD, Latah, ID

Built 1980 Load: 27.2 t ADT: 30

I 90RAMP EB ON

Fair

Over: S.FK.CD'A R.;EB ON RAMP

3.6 E. WALLACE, Shoshone, ID

Built 1964 Load: 27.2 t ADT: 20

FIRST ST

Fair

Over: BEAR CREEK;NW.CALDER BR

0.1 N. 0.1 W. CALDER, Shoshone, ID

Built 1960 Load: 27.2 t ADT: 100

STC3906;WARREN WGN

Fair

Over: N.FK.PAYETTE RIVER

16.0 N. 4.0 E. MCCALL, Valley, ID

Built 1969 Load: 27.2 t ADT: 530

NO DATA ENTERED

Fair

Over: SO FK SALMON

NO DATA ENTERED, Valley, ID

Built 1962 Load: 27.2 t ADT: 50

NO DATA ENTERED

Fair

Over: YELLOWJACKET CREEK

NO DATA ENTERED, Lemhi, ID

Built 1971 Load: 27.5 t ADT: 50

FDR 700

Fair

Over: ISABELLA CREEK

37 MILES FROM PIERCE ID, Clearwater, ID

Built 1962 Load: 27.9 t ADT: 30

NO DATA ENTERED

Fair

Over: DEATH CREEK

31 MI FROM PIERCE ID, Clearwater, ID

Built 1949 Load: 27.9 t ADT: 100

N 1600 E

Fair

Over: EGIN CANAL

0.3 S. EGIN, Fremont, ID

Built 1978 Load: 27.9 t ADT: 30

7TH AVENUE WEST

Fair

Over: T.F.NORTHSIDE MAIN CNL

0.6 S. GOODING, Gooding, ID

Built 1930 Load: 27.9 t ADT: 1,200

NO DATA ENTERED

Fair

Over: DEEP CR

NO DATA ENTERED, Idaho, ID

Built 1964 Load: 27.9 t ADT: 10

NO DATA ENTERED

Fair

Over: WALTON CREEK

ELK SUMMIT ROAD 362, Idaho, ID

Built 1953 Load: 27.9 t ADT: 20

E 620 N

Fair

Over: LONG ISLAND CANAL

3.2 N. 1.4 W. RIGBY, Jefferson, ID

Built 1967 Load: 27.9 t ADT: 70

STC 6709;N 4200 E

Fair

Over: DRY BED CR;S.LABELLE BR

1.0 S. 0.1 W. LABELLE, Jefferson, ID

Built 1973 Load: 27.9 t ADT: 160

NO DATA ENTERED

Fair

Over: DEEP CREEK

NO DATA ENTERED, Lemhi, ID

Built 1962 Load: 27.9 t ADT: 50

DOLLAR CREEK ROAD

Fair

Over: DOLLAR CK

5 MI N. OF WARM LAKE, Valley, ID

Built 1976 Load: 27.9 t ADT: 10

Dam Road

Fair

Over: CASCADE DAM SPILLWAY

CASCADE DAM, Valley, ID

Built 1947 Load: 28.0 t ADT: 100

STC3761;PLUMMER RD

Fair

Over: MIDDLETON CANAL

0.3 N. 1.0 E. STAR, Ada, ID

Built 1971 Load: 28.1 t ADT: 3,200

SMA 9833;MILWAUKEE

Fair

Over: RIDENBAUGH CANAL

IN BOISE;MILWAUKEE ST, Ada, ID

Built 1979 Load: 28.1 t ADT: 21,000

SMA 7363;EMERALD

Fair

Over: RIDENBAUGH CANAL

IN BOISE;EMERALD ST, Ada, ID

Built 1979 Load: 28.1 t ADT: 16,500

US 95

Fair

Over: E.FK.GOOSE CREEK

1.7 N. NEW MEADOWS, Adams, ID

Built 1978 Load: 28.1 t ADT: 3,200

ZIMS RD

Fair

Over: LITTLE SALMON RIVER

4.7 N. 0.4 W. NEW MEADOWS, Adams, ID

Built 1930 Load: 28.1 t ADT: 100

US 30

Fair

Over: DEER CROSSING

4.7 E. LAVA HOT SPRINGS, Bannock, ID

Built 1976 Load: 28.1 t ADT: 4,300

IRR BIA RTE 15

Fair

Over: BLACKFOOT RIVER

19 KM N.E. OF BLACKFOOT, Bingham, ID

Built 1978 Load: 28.1 t ADT: 100

STC1842;RISING RVR

Fair

Over: PEOPLES CANAL

5.1 N. 1.0 E. BLACKFOOT, Bingham, ID

Built 1993 Load: 28.1 t ADT: 550

STC 1840:WOLVERINE

Fair

Over: IDAHO CANAL

1.5S. 3.6E. FIRTH, Bingham, ID

Built 2002 Load: 28.1 t ADT: 290

3000N

Fair

Over: E.BRANCH BIG LOST RIVER

1.6 S. 0.6 E. MOORE, Butte, ID

Built 1992 Load: 28.1 t ADT: 50

2900N

Fair

Over: E.BRANCH BIG LOST RIVER

2.7 S. 0.8 E. MOORE, Butte, ID

Built 1920 Load: 28.1 t ADT: 160

STC 3730;RIVERSIDE

Fair

Over: DEER FLAT HIGH LINE CNL

1.8 N. 3.3 E. MARSING, Canyon, ID

Built 1986 Load: 28.1 t ADT: 970

E. SIMPLOT BLVD.

Fair

Over: INDIAN CREEK

IN CALDWELL, Canyon, ID

Built 1965 Load: 28.1 t ADT: 280

LINDEN ROAD

Fair

Over: MASON CREEK

1.0 S. 4.5 E. CALDWELL, Canyon, ID

Built 1974 Load: 28.1 t ADT: 6,700

50 EAST ROAD

Fair

Over: 'J' CANAL;SE.BURLEY BR

6.1S 0.5E BURLEY;580S-50E, Cassia, ID

Built 1975 Load: 28.1 t ADT: 100

MONTGOMERY RD

Fair

Over: KING HILL CREEK

0.7 N. 1.4 W. KING HILL, Elmore, ID

Built 1963 Load: 28.1 t ADT: 30

STC3840; SWEET-OLA

Fair

Over: SQUAW CREEK

4.5 S. 0.7 W. OLA, Gem, ID

Built 1928 Load: 28.1 t ADT: 450

2000 SOUTH ROAD

Fair

Over: T.F.NORTHSIDE MAIN CNL

2.0 S. 0.5 E. GOODING, Gooding, ID

Built 1930 Load: 28.1 t ADT: 150

1700 EAST ROAD

Fair

Over: DOG CREEK

4.9 N. 2.0 W. GOODING, Gooding, ID

Built 1974 Load: 28.1 t ADT: 80

N 4300 E

Fair

Over: HARRISON CANAL

0.3 N. 3.4 W. RIRIE, Jefferson, ID

Built 1973 Load: 28.1 t ADT: 60

OLD YELLOWSTONE HW

Fair

Over: BURGESS CANAL

0.5 S. 0.1 E. RIGBY, Jefferson, ID

Built 1940 Load: 28.1 t ADT: 3,600

QUAIL ROAD

Fair

Over: HATTER CREEK

1.5 S. 0.3 E. PRINCETON, Latah, ID

Built 1991 Load: 28.1 t ADT: 30

W 4000 N

Fair

Over: FARMERS CANAL

4.0 N. 0.3 W. REXBURG, Madison, ID

Built 1977 Load: 28.1 t ADT: 80

N 4000 E

Fair

Over: MOODY CREEK

2.1 N. 4.6 E. REXBURG, Madison, ID

Built 1977 Load: 28.1 t ADT: 540

S 6000 W

Fair

Over: TEXAS SLOUGH CANAL

5.34 SW REXBURG, Madison, ID

Built 1970 Load: 28.1 t ADT: 50

STC2863;600 WEST R

Fair

Over: 'D-9A' DRAIN

3.5 N. PAUL, Minidoka, ID

Built 1979 Load: 28.1 t ADT: 2,000

Showing 601-650 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.