State profile · Below median Poor share

Idaho bridge safety

According to the Federal Highway Administration's 2024 National Bridge Inventory, condition ratings, load ratings, and Poor-condition shares for every public highway bridge in Idaho.

4,616
Public bridges
29.5%
Good condition
4.9%
Poor condition

Idaho holds 4,616 public highway bridges (#37 of 52 by inventory) with a 4.9% Poor share (#33 of 52 by Poor share).

That is 4.9% of the state's inventory, against an average of 7.5% across the 54 states and territories with Poor-rated bridges on file, which places it 20 of 54 ordered from the lowest Poor share upward. A bridge is rated Poor when its weakest applicable component scores 4 or below on the inspecting agency's 0-9 scale, so the category is a maintenance and funding signal rather than a closure order or a live crossing-safety verdict.

Inventory: FHWA NBI 2024 · last ETL August 2026

Total Bridges

4,616

Public highway bridges in Idaho

Good Condition

29.5%

1,363 bridges rated 7-9

-20.5pp vs 50% benchmark

Poor Condition

4.9%

226 bridges whose lowest applicable component is rated 0-4

-2.6pp vs national avg 7.5%

Idaho vs national bridge condition

Idaho - Good condition share 29.5%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Idaho - Poor-condition share 16.3%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.5%.

Idaho in the national condition pattern

Each point is a state or territory in the FHWA NBI; the highlighted point is this profile.

Inventory size and Poor-condition share are different measures: Idaho has 4,616 bridges and a 4.9% Poor-condition share in the 2024 NBI, rank #20 of 54 jurisdictions ordered from the lowest share upward. The dashed comparisons mark the national average state rate and the midpoint of the plotted inventory range; neither is a live safety or closure threshold. Scatter plot of 54 data points. 0%10%20%30%40% 0k20k40k60k Public bridges in inventory (thousands) Poor-condition share (%) ID, Public bridges in inventory (thousands): 4.6k · Poor-condition share (%): 4.9%AL, Public bridges in inventory (thousands): 16.2k · Poor-condition share (%): 3.35%AK, Public bridges in inventory (thousands): 1.7k · Poor-condition share (%): 7.89%AZ, Public bridges in inventory (thousands): 8.6k · Poor-condition share (%): 1.15%AR, Public bridges in inventory (thousands): 13k · Poor-condition share (%): 5.43%CA, Public bridges in inventory (thousands): 25.8k · Poor-condition share (%): 5.91%CO, Public bridges in inventory (thousands): 9k · Poor-condition share (%): 4.82%CT, Public bridges in inventory (thousands): 4.4k · Poor-condition share (%): 4.72%DE, Public bridges in inventory (thousands): 0.9k · Poor-condition share (%): 1.26%DC, Public bridges in inventory (thousands): 0.3k · Poor-condition share (%): 1.95%FL, Public bridges in inventory (thousands): 13k · Poor-condition share (%): 2.79%GA, Public bridges in inventory (thousands): 15.1k · Poor-condition share (%): 1.59%GU, Public bridges in inventory (thousands): 0k · Poor-condition share (%): 12.77%HI, Public bridges in inventory (thousands): 1.2k · Poor-condition share (%): 6.53%IL, Public bridges in inventory (thousands): 26.9k · Poor-condition share (%): 9.35%IN, Public bridges in inventory (thousands): 19.5k · Poor-condition share (%): 5.22%IA, Public bridges in inventory (thousands): 23.7k · Poor-condition share (%): 19.16%KS, Public bridges in inventory (thousands): 24.9k · Poor-condition share (%): 5.26%KY, Public bridges in inventory (thousands): 14.5k · Poor-condition share (%): 7.37%LA, Public bridges in inventory (thousands): 12.7k · Poor-condition share (%): 11.48%ME, Public bridges in inventory (thousands): 2.5k · Poor-condition share (%): 15.41%MD, Public bridges in inventory (thousands): 5.5k · Poor-condition share (%): 4.56%MA, Public bridges in inventory (thousands): 5.3k · Poor-condition share (%): 8.88%MI, Public bridges in inventory (thousands): 11.4k · Poor-condition share (%): 11.27%MN, Public bridges in inventory (thousands): 13.5k · Poor-condition share (%): 4.44%MS, Public bridges in inventory (thousands): 16.7k · Poor-condition share (%): 6.03%MO, Public bridges in inventory (thousands): 24.6k · Poor-condition share (%): 8.95%MT, Public bridges in inventory (thousands): 5.2k · Poor-condition share (%): 6.81%NE, Public bridges in inventory (thousands): 15.4k · Poor-condition share (%): 7.9%NV, Public bridges in inventory (thousands): 2.1k · Poor-condition share (%): 1.14%NH, Public bridges in inventory (thousands): 2.5k · Poor-condition share (%): 7.51%NJ, Public bridges in inventory (thousands): 6.8k · Poor-condition share (%): 6.01%NM, Public bridges in inventory (thousands): 4k · Poor-condition share (%): 4.51%NY, Public bridges in inventory (thousands): 17.6k · Poor-condition share (%): 9.43%NC, Public bridges in inventory (thousands): 19.2k · Poor-condition share (%): 6.76%ND, Public bridges in inventory (thousands): 4.3k · Poor-condition share (%): 10.98%OH, Public bridges in inventory (thousands): 26.7k · Poor-condition share (%): 4.74%OK, Public bridges in inventory (thousands): 22.9k · Poor-condition share (%): 7.7%OR, Public bridges in inventory (thousands): 8.3k · Poor-condition share (%): 4.61%PA, Public bridges in inventory (thousands): 23.3k · Poor-condition share (%): 12.58%PR, Public bridges in inventory (thousands): 2.4k · Poor-condition share (%): 13.92%RI, Public bridges in inventory (thousands): 0.8k · Poor-condition share (%): 15.2%SC, Public bridges in inventory (thousands): 9.5k · Poor-condition share (%): 6.17%SD, Public bridges in inventory (thousands): 5.9k · Poor-condition share (%): 16.36%TN, Public bridges in inventory (thousands): 20.4k · Poor-condition share (%): 4.41%TX, Public bridges in inventory (thousands): 56.7k · Poor-condition share (%): 1.23%UT, Public bridges in inventory (thousands): 3.1k · Poor-condition share (%): 2.91%VT, Public bridges in inventory (thousands): 2.9k · Poor-condition share (%): 2.9%VI, Public bridges in inventory (thousands): 0k · Poor-condition share (%): 29.17%VA, Public bridges in inventory (thousands): 14.1k · Poor-condition share (%): 3.39%WA, Public bridges in inventory (thousands): 8.5k · Poor-condition share (%): 5.45%WV, Public bridges in inventory (thousands): 7.3k · Poor-condition share (%): 18.64%WI, Public bridges in inventory (thousands): 14.4k · Poor-condition share (%): 6.52%WY, Public bridges in inventory (thousands): 3.1k · Poor-condition share (%): 6.51%
Inventory size and Poor-condition share are different measures: Idaho has 4,616 bridges and a 4.9% Poor-condition share in the 2024 NBI, rank #20 of 54 jurisdictions ordered from the lowest share upward. The dashed comparisons mark the national average state rate and the midpoint of the plotted inventory range; neither is a live safety or closure threshold.

Idaho vs all states by public bridge inventory

Where this state's FHWA NBI public-highway bridge count sits among every state and territory on PlainBridges

4,616 37th of 54 higher than 17 of 54 states

States and territories, banded by public bridge inventory size

Each bar is a band; taller bars hold more states. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.

Source FHWA National Bridge Inventory · 2024

Read the rank neighborhood for Idaho

The highlighted point is Idaho: 4,616 bridges and 4.90% in Poor condition, rank #20 of 54 jurisdictions ordered from the lowest share upward. The five jurisdictions immediately above and below Idaho on that same Poor-share ordering:

  • Ohio: 26,729 bridges · 4.74% Poor
  • Colorado: 8,965 bridges · 4.82% Poor
  • Idaho: 4,616 bridges · 4.90% Poor
  • Indiana: 19,495 bridges · 5.22% Poor
  • Kansas: 24,894 bridges · 5.26% Poor

The full national sortable table lives on the rankings page.

Material families in Idaho

Exclusive FHWA material families across all 4,616 bridges in this state; continuous variants fold into the parent family. Orthogonal to the Poor-share scatter above.

Who maintains Idaho’s inventory

State agency holds 29.8% of the 4,616 public highway bridges filed under Idaho in the 2024 NBI, the agency-of-record split for this state, not a condition verdict.

When Idaho’s bridges were built

Pre-1950 construction accounts for 7.0% of the 4,616 bridges with a recorded original year in Idaho. Era bands are orthogonal to the Poor-share ranking above.

Condition Distribution

Idaho29.5%65.6%GoodFairPoor
Bridge inventory deck-condition mix - Idaho (FHWA NBI)

Counties (44)

Ada 299 Adams 87 Bannock 124 Bear Lake 34 Benewah 47 Bingham 263 Blaine 96 Boise 88 Bonner 104 Bonneville 213 Boundary 83 Butte 32 Camas 61 Canyon 292 Caribou 45 Cassia 116 Clark 40 Clearwater 88 Custer 128 Elmore 97 Franklin 23 Fremont 137 Gem 57 Gooding 80 Idaho 215 Jefferson 127 Jerome 110 Kootenai 154 Latah 115 Lemhi 112 Lewis 21 Lincoln 53 Madison 80 Minidoka 66 Nez Perce 71 Oneida 23 Owyhee 48 Payette 65 Power 70 Shoshone 260 Teton 37 Twin Falls 126 Valley 149 Washington 80

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.

OH

Ohio

4.74% top marginal rate
Structure
Progressive
Burden @ $100K
$26,729

CO

Colorado

4.82% top marginal rate
Structure
Progressive
Burden @ $100K
$8,965
Selected

ID

Idaho

4.90% top marginal rate
Structure
Progressive
Burden @ $100K
$4,616

IN

Indiana

5.22% top marginal rate
Structure
Progressive
Burden @ $100K
$19,495

KS

Kansas

5.26% top marginal rate
Structure
Progressive
Burden @ $100K
$24,894

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

RIVER ROAD

Poor

Over: VINSON WASH

2.0 N. 2.6 W. GRAND VIEW, Owyhee, ID

Built 1930 Load: 0.9 t ADT: 60

SWAMP ROAD

Poor

Over: CAMAS CREEK

1.5 S. 0.3 E. HILL CITY, Camas, ID

Built 1965 Load: 1.8 t ADT: 40

ELK SUMMIT RD

Poor

Over: SOUTH FORK SALMON RIVER

14.6 N 4.3 W YELLOW PINE, Valley, ID

Built 1934 Load: 1.8 t ADT: 10

ROAD 50343

Poor

Over: LOGAN CREEK

NO DATA ENTERED, Valley, ID

Built 1980 Load: 2.6 t ADT: 50

200 SOUTH ROAD

Poor

Over: CAMAS CREEK

1.9 S. 6.8 E. FAIRFIELD, Camas, ID

Built 1920 Load: 2.7 t ADT: 30

All Bridges in Idaho

US 91

Good

Over: RESERVATION CANAL

1.4 NE FIRTH, Bingham, ID

Built 2000 Load: 39.9 t ADT: 3,600

US 93

Good

Over: SPRING CREEK

2.4 N. ARCO, Butte, ID

Built 1962 Load: 39.9 t ADT: 2,400

STC 3856; FRANKLIN

Good

Over: FIVE MILE CREEK

IN MERIDIAN, Ada, ID

Built 2004 Load: 39.9 t ADT: 23,500

STC 4710;ROCKY CYN

Good

Over: ROCK CREEK

9.4 S. 2.3 W. COTTONWOOD, Idaho, ID

Built 1998 Load: 39.9 t ADT: 210

RIVER ROAD

Good

Over: BEDROCK CREEK;NW.LENORE

0.8 N. 1.8 W. LENORE, Nez Perce, ID

Built 1982 Load: 39.9 t ADT: 100

SOUTH BLVD

Good

Over: US 26 NB-SB;S.BLVD GS

IN IDAHO FALLS, Bonneville, ID

Built 2001 Load: 39.9 t ADT: 2,200

BUNCO ROAD

Good

Over: BUNCO RD; US 95 IC

1.6 S. ATHOL, Kootenai, ID

Built 2012 Load: 39.9 t ADT: 2,900

3501: EAGLE CREEK

Good

Over: Eagle Creek

11 mi S of Zaza Road, Nez Perce, ID

Built 1974 Load: 39.9 t ADT: 25

NFSR 223

Good

Over: GLOVER CREEK

15 MILES FROM LOWELL, Idaho, ID

Built 2014 Load: 39.9 t ADT: 40

IRR BIA RTE 904

Good

Over: OWYHEE RIVER

17.4 KM NW OF OWYHEE, Owyhee, ID

Built 1987 Load: 40.0 t ADT: 20

SH 3

Good

Over: WILLOW CREEK

10.2 S. ROSE LAKE, Kootenai, ID

Built 2014 Load: 40.2 t ADT: 1,900

US 91 NBL

Good

Over: I 86 EB-WB; CHUBBUCK IC

IN CHUBBUCK, Bannock, ID

Built 2013 Load: 40.2 t ADT: 9,750

BASELINE ROAD

Good

Over: RAFT RIVER

0.2S 0.4W RAFT RIVER IC, Cassia, ID

Built 2019 Load: 40.2 t ADT: 100

STC 4715;CLEAR CRK

Good

Over: CLEAR CREEK

0.7 S. 1.3 E. KOOSKIA, Idaho, ID

Built 2021 Load: 40.2 t ADT: 820

OLD HWY ROAD

Good

Over: S.FK.COEUR DALENE RIVER

0.3 N. 1.6 E. MULLAN, Shoshone, ID

Built 2014 Load: 40.2 t ADT: 990

SH 78

Good

Over: SCORPION CREEK

5.7 N 0.6 W MURPHY, Owyhee, ID

Built 2013 Load: 40.2 t ADT: 1,200

FOREST ROAD 1858

Good

Over: NEWSOME CREEK

NEWSOME TOWN SITE, Idaho, ID

Built 1966 Load: 40.2 t ADT: 40

SH 32

Good

Over: BADGER CREEK

0.5 S. FELT, Teton, ID

Built 2016 Load: 40.5 t ADT: 1,600

SH 36

Good

Over: BEAR RIVER

1.0 W. PRESTON, Franklin, ID

Built 2018 Load: 40.5 t ADT: 3,000

STC8200;JENKINS RD

Good

Over: GALLOWAY CANAL

0.9 N. 1.2 W. WEISER, Washington, ID

Built 1971 Load: 40.5 t ADT: 810

NFSR 50446

Good

Over: FISHER CREEK TRIBUTARY

NO DATA ENTERED, Valley, ID

Built 1965 Load: 40.5 t ADT: 50

I 86B AM. FALLS IC

Good

Over: I 86 EB-WB; AM. FALLS IC

1.6 E. AMERICAN FALLS, Power, ID

Built 2011 Load: 40.8 t ADT: 3,900

SH 21

Good

Over: MORES CREEK;BIG GULCH

5.7 S. IDAHO CITY, Boise, ID

Built 1990 Load: 40.8 t ADT: 2,000

OLD US 30

Good

Over: UPRR;E.HAMMETT RR OP

1.5 E. HAMMETT, Elmore, ID

Built 2019 Load: 40.8 t ADT: 110

SH 69;MERIDIAN RD

Good

Over: I 84;SH 69 MERIDIAN IC

MERIDIAN SCL, Ada, ID

Built 2015 Load: 40.8 t ADT: 21,000

I 90 EBL

Good

Over: ELIZABETH PARK

1.8 E. KELLOGG, Shoshone, ID

Built 2022 Load: 40.8 t ADT: 6,750

SH 75

Good

Over: NORTH GOODING CANAL

6.3 N. SHOSHONE, Lincoln, ID

Built 2013 Load: 40.8 t ADT: 4,200

US 93

Good

Over: SALMON RIVER;CHALLIS BR.

2.6 S. CHALLIS, Custer, ID

Built 1995 Load: 40.8 t ADT: 1,400

US 95

Good

Over: WI&M RAILROAD

14.5 N. MOSCOW, Latah, ID

Built 2022 Load: 40.8 t ADT: 5,500

STC3879;BURTON LN

Good

Over: LITTLE WEISER RIVER

1.8 S. 1.0 E. CAMBRIDGE, Washington, ID

Built 1991 Load: 40.8 t ADT: 190

S4795;GNSEE-JLETTA

Good

Over: LITTLE POTLATCH CREEK

3.9 N. 6.2 E. GENESEE, Latah, ID

Built 1977 Load: 40.8 t ADT: 30

ROSE ROAD

Good

Over: I 15; ROSE ROAD IC

5.2 N. BLACKFOOT, Bingham, ID

Built 2020 Load: 40.8 t ADT: 1,300

GRIFFIN LOOP SOUTH

Good

Over: W. BR. LITTLE WOOD RIVER

2.9 S. CAREY, Blaine, ID

Built 1978 Load: 40.8 t ADT: 8

MORMON ROAD

Good

Over: CAMAS CREEK

3.8 S. 0.5 W. FAIRFIELD, Camas, ID

Built 2016 Load: 40.8 t ADT: 30

E 2800 S

Good

Over: I 84 EB-WB;E 2800 S GS

3.5 W. WENDELL, Gooding, ID

Built 1972 Load: 40.8 t ADT: 160

STC2866;300 N. RD.

Good

Over: MAIN NORTHSIDE CANAL

ACEQUIA, Minidoka, ID

Built 2001 Load: 40.8 t ADT: 270

S. KNAPP AVE

Good

Over: RIDENBAUGH CANAL

2.0 S. 2.4 E. MERIDIAN, Ada, ID

Built 2005 Load: 40.8 t ADT: 1,900

S. THOMAS LANE

Good

Over: RIDENBAUGH CANAL

3.2 E. MERIDIAN, Ada, ID

Built 2002 Load: 40.8 t ADT: 50

NF ROAD 105

Good

Over: INDIAN CREEK

2.4 N 2.8 E CUPRUM, Adams, ID

Built 2010 Load: 40.8 t ADT: 80

LONG GULCH ROAD

Good

Over: RATTLESNAKE CREEK

4.9 N 5.2 W PRAIRIE, Elmore, ID

Built 2018 Load: 40.8 t ADT: 120

STC 3888;SUPERIOR

Good

Over: RUSH CREEK

IN CAMBRIDGE, Washington, ID

Built 2009 Load: 40.8 t ADT: 300

ZUMWALT ROAD

Good

Over: S.FK. COTTONWOOD CREEK

4.8 N. 3.0 W. GRANGEVILLE, Idaho, ID

Built 2017 Load: 40.8 t ADT: 50

ELK CREEK ROAD

Good

Over: LITTLE SALMON RIVER

14.4 S. RIGGINS, Idaho, ID

Built 2004 Load: 40.8 t ADT: 70

S 4TH OF JULY CK

Good

Over: FOURTH OF JULY CREEK

AT ROSE LAKE JCT., Kootenai, ID

Built 1962 Load: 40.8 t ADT: 20

US 95 NBL

Good

Over: FIGHTING CREEK

12.7 N. WORLEY, Kootenai, ID

Built 2006 Load: 40.8 t ADT: 3,350

CUSTER ROAD

Good

Over: SULPHUR CREEK

3.8 S. 0.2 W. MAY, Custer, ID

Built 2012 Load: 40.8 t ADT: 100

FS ROUTE NO. 2694

Good

Over: GOOSE CREEK

GOOSE CREEK, Bonner, ID

Built 1990 Load: 40.8 t ADT: 50

FDR 103

Good

Over: CAMP CREEK

23 MILES FROM PIERCE ID, Idaho, ID

Built 1968 Load: 40.8 t ADT: 30

NO DATA ENTERED

Good

Over: EAST FORK WEISER RIVER

NO DATA ENTERED, Adams, ID

Built 1963 Load: 40.8 t ADT: 50

60030

Good

Over: SALMON RIVER

SALMON RIVER NEAR PINE CR, Lemhi, ID

Built 2012 Load: 40.8 t ADT: 350

Showing 3,851-3,900 of 4,616 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.

What to do with this

Use Idaho's inventory picture to drill to a county or a specific span.

NBI condition ratings are inventory snapshots, not live crossing-safety verdicts.

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Idaho Good/Fair/Poor shares and county rollups on this page are computed from the same NBI extract as the national boards; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.