State profile · Below median Poor share

Idaho bridge safety

Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Idaho, based on the FHWA National Bridge Inventory.

1,742
Public bridges
33.3%
Good condition
5.5%
Poor condition

Data updated May 2026

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 whose lowest applicable component is rated 0-4

-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 - Poor-condition share 18.4%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Idaho35.4%58.7%GoodFairPoor
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 by Poor-condition share (lower share = better)

States are ranked by the share of bridges whose lowest applicable component rating is 4 or below. This describes recorded condition; it does not measure funding effectiveness or live crossing safety. States here sit immediately above and below Idaho on the same metric.

KS

Kansas

5.25% top marginal rate
Structure
Progressive
Burden @ $100K
$23,867

WY

Wyoming

5.41% top marginal rate
Structure
Progressive
Burden @ $100K
$3,181
Selected

ID

Idaho

5.51% top marginal rate
Structure
Progressive
Burden @ $100K
$1,742

MS

Mississippi

5.92% top marginal rate
Structure
Progressive
Burden @ $100K
$16,823

SC

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 the portal's composite display score. Inspection intervals are risk-based under current NBIS rules.

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

Poor

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

LYNWOOD ROAD

Fair

Over: MORA CANAL

8.8 S. 1.6 W. NAMPA, Canyon, ID

Built 1998 Load: 30.8 t ADT: 90

STC 1769;RIVER RD

Fair

Over: BEAR R;CHEESECAKE FAC BR

4.5 S. 2.5 W. GRACE, Caribou, ID

Built 1975 Load: 30.8 t ADT: 140

STATELINE RD;WY114

Fair

Over: TINCUP CREEK

3.5 Miles N. of ETNA, Caribou, ID

Built 1970 Load: 30.8 t ADT: 121

50 WEST ROAD

Fair

Over: 'H' CANAL

2.6S 0.1W BURLEY;220S-50W, Cassia, ID

Built 1989 Load: 30.8 t ADT: 450

I 84B

Fair

Over: UPRR;N.HAMMETT RR OP

0.5 N. HAMMETT, Elmore, ID

Built 1973 Load: 30.8 t ADT: 1,700

I 84B ;FIRST AVE

Fair

Over: LITTLE CANYON CREEK

IN GLENNS FERRY;FIRST AVE, Elmore, ID

Built 1962 Load: 30.8 t ADT: 2,800

LITTLE BEAR RIDGE

Fair

Over: LITTLE BEAR CREEK

0.1 N. 2.0 E. TROY, Latah, ID

Built 1965 Load: 30.8 t ADT: 350

INDIAN CREEK RD

Fair

Over: INDIAN CREEK(#3)

22.0 NW SALMON, Lemhi, ID

Built 1970 Load: 30.8 t ADT: 15

SH 51

Fair

Over: BRUNEAU RIVER SLOUGH

0.5 W. BRUNEAU, Owyhee, ID

Built 1955 Load: 30.8 t ADT: 1,200

THEATRE ROAD

Fair

Over: S.FK.CD'A R;SMELTERVILLE

0.4 N. 0.1 W.SMELTERVILLE, Shoshone, ID

Built 1963 Load: 30.8 t ADT: 200

FOREST ROAD 1194

Fair

Over: SO. FK. RED RIVER

NO DATA ENTERED, Idaho, ID

Built 1969 Load: 31.1 t ADT: 40

FOREST ROAD 1809

Fair

Over: AMERICAN RIVER

NO DATA ENTERED, Idaho, ID

Built 1961 Load: 31.1 t ADT: 50

FS ROUTE NO. 2798

Fair

Over: CANUCK CREEK

CANUCK CR, Boundary, ID

Built 1957 Load: 31.4 t ADT: 50

FDR 292

Fair

Over: PALOUSE RIVER

2 MI E OF STATE HWY 6, Latah, ID

Built 1959 Load: 31.4 t ADT: 20

E 600 N

Fair

Over: CROSSCUT CANAL

1.9 S. 1.8 W. CHESTER, Fremont, ID

Built 1937 Load: 31.5 t ADT: 20

STC9589;SALES YARD

Fair

Over: FARMERS COOP CANAL

1.7 S. 0.2 W. EMMETT, Gem, ID

Built 1970 Load: 31.5 t ADT: 320

MEDIMONT ROAD

Fair

Over: CAVE LAKE CHANNEL

0.4 S. 0.5 E. MEDIMONT, Kootenai, ID

Built 1991 Load: 31.5 t ADT: 50

WIGGINS ROAD

Fair

Over: KEITHLY CREEK

2.7 N. MIDVALE, Washington, ID

Built 1984 Load: 31.5 t ADT: 50

SMA 7030;STATE ST

Fair

Over: DRY CREEK

AT EAGLE WCL, Ada, ID

Built 1959 Load: 31.8 t ADT: 4,700

STC 3770;STAR RD

Fair

Over: PHYLLIS CANAL

1.8 S. STAR, Ada, ID

Built 1967 Load: 31.8 t ADT: 11,000

SH 75

Fair

Over: REDFISH LAKE CREEK

5.6 S. STANLEY, Custer, ID

Built 1960 Load: 31.8 t ADT: 1,100

I 84 WBL

Fair

Over: CANYON CREEK

5.5 W. MOUNTAIN HOME, Elmore, ID

Built 1959 Load: 31.8 t ADT: 14,000

I 90 EBL & WBL

Fair

Over: FOURTH OF JULY CREEK

19.0 E. COEUR D'ALENE, Kootenai, ID

Built 1958 Load: 31.8 t ADT: 14,500

W 1ST SOUTH ST

Fair

Over: REXBURG CANAL

IN REXBURG; W 1ST S ST, Madison, ID

Built 2019 Load: 31.8 t ADT: 800

SH 78

Fair

Over: BROWN CREEK

5.6 W. HAMMETT, Owyhee, ID

Built 1954 Load: 31.8 t ADT: 460

S3706;PLEASANT VLY

Fair

Over: JORDON CREEK;PLEASANT BR

4.8 E. IDA-ORE BORDER, Owyhee, ID

Built 1930 Load: 31.8 t ADT: 50

S5765;SILVR VALLEY

Fair

Over: S.FK.COEUR D'ALENE RIVER

0.9 N. 1.6 W. OSBURN, Shoshone, ID

Built 1949 Load: 31.8 t ADT: 1,400

EAST FORK ROAD

Fair

Over: E.FK. OF S.FK.SALMON RVR

AT YELLOW PINE, Valley, ID

Built 1955 Load: 31.8 t ADT: 40

ROAD 615

Fair

Over: CANYON CREEK TRIBUTARY

NO DATA ENTERED, Shoshone, ID

Built 1954 Load: 32.1 t ADT: 50

FS ROUTE NO. 1222

Fair

Over: GOLD CREEK

GOLD CREEK, Shoshone, ID

Built 1963 Load: 32.1 t ADT: 50

W BLACKROCK ROAD

Fair

Over: PORTNEUF R;NW.INKOM BR

0.2 N. 4.0 W. INKOM, Bannock, ID

Built 1948 Load: 32.4 t ADT: 100

IRR BIA RTE 33

Fair

Over: MAIN CANAL

10 KM SOUTH OF BLACKFOOT, Bingham, ID

Built 1972 Load: 32.4 t ADT: 80

N.FK. BOISE R. RD.

Fair

Over: NORTH FORK BOISE RIVER

(DEER PARK BRIDGE), Boise, ID

Built 1949 Load: 32.4 t ADT: 59

FS ROUTE 1013

Fair

Over: UPPER PRIEST RIVER

UPPER PRIEST RIVER, Bonner, ID

Built 1965 Load: 32.4 t ADT: 40

FS ROUTE 1013

Fair

Over: HUGHES FORK CR

18.5 MI FROM NORDMAN, ID., Bonner, ID

Built 1965 Load: 32.4 t ADT: 40

HOLLOW ROAD

Fair

Over: 'C' LINE EAST CANAL

9.1 N. 1.0 E. CALDWELL, Canyon, ID

Built 1977 Load: 32.4 t ADT: 50

FDR 670

Fair

Over: WASHINGTON CREEK

22 MILES FROM PIERCE ID, Clearwater, ID

Built 1953 Load: 32.4 t ADT: 20

N 4000 E

Fair

Over: BURGESS CANAL

0.5 S. 0.6 E. RIGBY, Jefferson, ID

Built 1976 Load: 32.4 t ADT: 210

FS ROUTE NO. 1218

Fair

Over: GOLD CREEK

GOLD CREEK, Shoshone, ID

Built 1961 Load: 32.4 t ADT: 50

FS ROUTE NO. 301

Fair

Over: LITTLE NF CLEARWATER

LITTLE NF CLEARWATER, Shoshone, ID

Built 1951 Load: 32.4 t ADT: 40

FS ROUTE NO. 265

Fair

Over: TEPEE CREEK

TEPEE CR, Shoshone, ID

Built 1976 Load: 32.4 t ADT: 50

STC 1811;PEGRAM RD

Fair

Over: BEAR RIVER;PEGRAM BRIDGE

0.8 W. PEGRAM, Bear Lake, ID

Built 1970 Load: 32.7 t ADT: 100

SH 39

Fair

Over: NORTH LOW LINE CANAL

2.5 N. ABERDEEN, Bingham, ID

Built 1969 Load: 32.7 t ADT: 2,000

SPUR 348J

Fair

Over: PIKES FORK CREEK

NEAR NFSR 312/348J JUNCT, Boise, ID

Built 1985 Load: 32.7 t ADT: 10

I 15 NBL

Fair

Over: GREAT WESTERN CANAL

4.1 N. IDAHO FALLS, Bonneville, ID

Built 1962 Load: 32.7 t ADT: 3,200

NO DATA ENTERED

Fair

Over: BALL CREEK

BALL CREEK, Boundary, ID

Built 1963 Load: 32.7 t ADT: 50

2800 N

Fair

Over: E.BRANCH BIG LOST RIVER

3.1 N. 2.2 W. ARCO, Butte, ID

Built 1920 Load: 32.7 t ADT: 40

SMA7808;MIDDLETON

Fair

Over: MILL SLOUGH

MIDDLETON NE CITY LIMITS, Canyon, ID

Built 1999 Load: 32.7 t ADT: 3,400

STC 3790;ALLENDALE

Fair

Over: GOLDEN GATE CANAL

0.6 S. 2.0 E. WILDER, Canyon, ID

Built 1992 Load: 32.7 t ADT: 240

TUCKER ROAD

Fair

Over: LOW LINE CANAL

1.0 S. 4.0 E. WILDER, Canyon, ID

Built 1997 Load: 32.7 t ADT: 70

Showing 751-800 of 1,742 bridges

Related

All states → | National rankings → | Understanding conditions → | Retired SD term explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges.

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). Poor condition is an inspection-record category, not a closure or unsafe-to-cross designation. Consult the bridge owner for current status.

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.

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.