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

SH 57

Good

Over: KALISPELL CREEK

3.2 S. NORDMAN, Bonner, ID

Built 2020 Load: 41.1 t ADT: 840

STC5752;CDA RVR RD

Good

Over: I 90 EB-WB;KINGSTON IC

7.2 W. KELLOGG, Shoshone, ID

Built 2018 Load: 41.1 t ADT: 2,200

TRAPPER CREEK RD

Good

Over: TRAPPER CREEK

4.5 S. 0.8 E. PINEHURST, Shoshone, ID

Built 2021 Load: 41.1 t ADT: 30

US 95

Good

Over: LAPWAI CREEK

2.4 N. 1.1 E. WINCHESTER, Lewis, ID

Built 2020 Load: 41.1 t ADT: 3,500

HANLEY PLACE

Good

Over: WILLOW CREEK

6.95 S. EMMETT, Ada, ID

Built 2023 Load: 41.1 t ADT: 40

FS ROUTE NO. 805

Good

Over: WEST FORK EAGLE CREEK

WEST FORK EAGLE CREEK, Shoshone, ID

Built 1957 Load: 41.1 t ADT: 50

FDR 595

Good

Over: CROOKED FORK

25 MILES TO POWELL R S, Clearwater, ID

Built 1972 Load: 41.1 t ADT: 30

NO DATA ENTERED

Good

Over: NO DATA ENTERED

WENDOVER CAMP GROUND, Idaho, ID

Built 2011 Load: 41.1 t ADT: 40

DEADWD.-SCT.MT.RD.

Good

Over: EAST BIG PINE CREEK

4 MI NE DANSKIN, Boise, ID

Built 2007 Load: 41.1 t ADT: 15

NFSR 421

Good

Over: FAWN CREEK

6 MI S. OF LAKE CASCADE, Valley, ID

Built 2011 Load: 41.1 t ADT: 10

NFSR 50246

Good

Over: LAKE CREEK

NO DATA ENTERED, Idaho, ID

Built 1976 Load: 41.1 t ADT: 40

I 90 WBL

Good

Over: ELIZABETH PARK

1.8 E. KELLOGG, Shoshone, ID

Built 2023 Load: 41.5 t ADT: 6,750

I 90B LOOP

Good

Over: S.FK.COEUR DALENE RIVER

IN MULLAN, Shoshone, ID

Built 2014 Load: 41.5 t ADT: 990

SH 200

Good

Over: TRESTLE CREEK

3.0 W. HOPE, Bonner, ID

Built 2013 Load: 41.5 t ADT: 3,400

FT HALL MAIN CNL

Good

Over: HARVEST SPG BLVD

IN CHUBBUCK, Bannock, ID

Built 2022 Load: 41.5 t ADT: 500

US 95

Good

Over: LAPWAI CREEK

1.6 N. 1.0 E. WINCHESTER, Lewis, ID

Built 2019 Load: 41.5 t ADT: 3,500

STC5727;RAMSEY RD

Good

Over: BNSF RR; DIAGONAL RD

5.2 N. HAYDEN, Kootenai, ID

Built 2021 Load: 41.5 t ADT: 4,900

EDNA CK.-L.OWL RD.

Good

Over: PIKES FORK CREEK

3 MI ENE OF EDNA CR CG, Boise, ID

Built 2005 Load: 41.5 t ADT: 50

DITCH CREEK RD

Good

Over: DITCH CREEK

10 MI NE OF WARM LAKE, Valley, ID

Built 2009 Load: 41.5 t ADT: 50

S FK OF SALMON RIV

Good

Over: MORMON CREEK

5 MI S OF STOLLE MEADOWS, Valley, ID

Built 2011 Load: 41.5 t ADT: 12

PARADISE VALLEY RO

Good

Over: CABIN CREEK

1 MI N OF WARM LAKE, Valley, ID

Built 2013 Load: 41.5 t ADT: 20

SH 34

Good

Over: TINCUP CREEK

12 E. WAYAN, Caribou, ID

Built 1969 Load: 41.7 t ADT: 540

SH 34

Good

Over: TINCUP CREEK

12.1 E. WAYAN, Caribou, ID

Built 1969 Load: 41.7 t ADT: 540

SH 48

Good

Over: HARRISON CANAL

8.6 E. RIGBY, Jefferson, ID

Built 1983 Load: 41.7 t ADT: 2,000

US 91

Good

Over: UPRR;REDROCK OVERPASS

6.7 S. DOWNEY, Bannock, ID

Built 1995 Load: 41.7 t ADT: 1,500

US 95

Good

Over: MONROE CREEK

3.8 N. WEISER NBCL, Washington, ID

Built 1990 Load: 41.7 t ADT: 4,400

US 95

Good

Over: PACK RIVER;N COLBURN BR.

2.2 N. COLBURN, Bonner, ID

Built 1988 Load: 41.7 t ADT: 8,500

TRAIL CREEK ROAD

Good

Over: BLACKFOOT RIVER

15.6 N.E. SODA SPRINGS, Caribou, ID

Built 2001 Load: 41.7 t ADT: 100

STP 8973;ORCHARD

Good

Over: SETTLERS CANAL 35/36 ST.

IN GARDEN CITY;ORCHARD ST, Ada, ID

Built 1989 Load: 41.7 t ADT: 11,500

SMA9243;VICTORY RD

Good

Over: RIDENBAUGH CANAL

2.5 S. 0.5 W. MERIDIAN, Ada, ID

Built 1984 Load: 41.7 t ADT: 3,800

1ST AVE NORTH

Good

Over: INDIAN CREEK

IN NAMPA;1ST AVE N, Canyon, ID

Built 2002 Load: 41.7 t ADT: 800

BISHOP ROAD

Good

Over: FARMERS COOP CANAL

1.5 S 1.2 W LETHA, Gem, ID

Built 2010 Load: 41.7 t ADT: 30

OASIS ROAD

Good

Over: D LINE CANAL

11.5S. 2.5E. NEW PLYMOUTH, Payette, ID

Built 2000 Load: 41.7 t ADT: 680

STC 3888;MILL ROAD

Good

Over: WEISER RIVER

0.5N 1.7E CAMBRIDGE, Washington, ID

Built 2002 Load: 41.7 t ADT: 300

GRANDAD ROAD

Good

Over: N.FK.CLEARWATER;GRANDAD

2.4 N. 12.3 E. ELK RIVER, Clearwater, ID

Built 1971 Load: 41.7 t ADT: 100

STC4713;WDLAND GRD

Good

Over: LOLO CREEK

4.2 N 4.6 W WOODLAND, Idaho, ID

Built 2007 Load: 41.7 t ADT: 30

ROSE CREEK ROAD

Good

Over: ROSE CREEK

2.0 S. 4.0 W. WORLEY, Benewah, ID

Built 2006 Load: 41.7 t ADT: 20

3800 NORTH RD

Good

Over: BIG LOST RIVER

1.0 N. DARLINGTON, Custer, ID

Built 2007 Load: 41.7 t ADT: 30

W. CAMAS CREEK RD

Good

Over: W. CAMAS CREEK

7.2 NW. KILGORE, Clark, ID

Built 1970 Load: 41.7 t ADT: 110

IRR BIA RTE 91

Good

Over: BLACKFOOT RIVER

5 KM SW OF BLACKFOOT, Bingham, ID

Built 2015 Load: 41.8 t ADT: 85

SH 19

Good

Over: SUCCOR CREEK

0.2 W. HOMEDALE, Owyhee, ID

Built 2017 Load: 41.8 t ADT: 2,400

US 26

Good

Over: ABERDEEN CANAL

4.7 W. BLACKFOOT, Bingham, ID

Built 2020 Load: 41.8 t ADT: 3,000

I 84 WBL

Good

Over: UPRR; GOWEN SPUR

BOISE SCL, Ada, ID

Built 2015 Load: 41.8 t ADT: 25,000

SH 75

Good

Over: SALMON RIVER;E. CLAYTON

5 E. CLAYTON, Custer, ID

Built 2014 Load: 41.8 t ADT: 590

US 95

Good

Over: SAND HOLLOW CREEK

1.6 E. PARMA, Canyon, ID

Built 2017 Load: 41.8 t ADT: 3,900

S7241;NRTHGTE PKWY

Good

Over: I 15 NB-SB;NORTHGATE IC

4.0 N POCATELLO, Bannock, ID

Built 2020 Load: 41.8 t ADT: 28,500

FISHERMANS DR

Good

Over: HENRYS FK SNAKE RIVER

0.4 S. 0.8 W. WARM RIVER, Fremont, ID

Built 2015 Load: 41.8 t ADT: 175

PRATT CREEK ROAD

Good

Over: PRATT CREEK

2.0 E. BAKER, Lemhi, ID

Built 2015 Load: 41.8 t ADT: 33

FS ROUTE 281

Good

Over: COW CREEK

8.6 MI FROM FH.18 JCT., Boundary, ID

Built 1984 Load: 41.8 t ADT: 40

NO DATA ENTERED

Good

Over: OROGRANDE CREEK

OROGRANDE CREEK 1, Clearwater, ID

Built 1956 Load: 41.8 t ADT: 145

Showing 3,901-3,950 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.