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 55

Good

Over: FARMERS UNION CANAL

1.2 N. OF SH 44, Ada, ID

Built 1997 Load: 47.2 t ADT: 17,000

STC2816;BULLION ST

Good

Over: BIG WOOD RIVER

0.3 S. 0.4 W. HAILEY, Blaine, ID

Built 1972 Load: 47.2 t ADT: 160

NORWOOD RD

Good

Over: MUD CREEK

0.2 S. 1.5 W. DONNELLY, Valley, ID

Built 2004 Load: 47.2 t ADT: 870

BARKDULL RD

Good

Over: LANES GULCH

0.25 S EXIT 21(COLDWATER), Power, ID

Built 1981 Load: 47.2 t ADT: 100

300 EAST ROAD

Good

Over: L CANAL

1.5 S. 3.0 E. JEROME, Jerome, ID

Built 2003 Load: 47.2 t ADT: 510

STC2781;470 N. RD.

Good

Over: 700 CREEK

4.3 N. 6.5 W. SHOSHONE, Lincoln, ID

Built 1965 Load: 47.2 t ADT: 340

100 NORTH ROAD

Good

Over: A CANAL

1.0 N. 1.9 E. RUPERT, Minidoka, ID

Built 2009 Load: 47.2 t ADT: 150

S9783;LOCUST GROVE

Good

Over: RIDENBAUGH CANAL

3.2 S. 0.8 E. MERIDIAN, Ada, ID

Built 1984 Load: 47.2 t ADT: 7,800

STC3928;S EAGLE RD

Good

Over: NEW YORK CANAL

0.3 S. 3.3 E. KUNA, Ada, ID

Built 1997 Load: 47.2 t ADT: 1,100

STC 3938;ROSEBERRY

Good

Over: MUD CREEK

1.6 W. DONNELLY, Valley, ID

Built 2004 Load: 47.2 t ADT: 930

STC3895;JOHNSON CR

Good

Over: RIORDAN CREEK

3.5 S. 0.3 E. YELLOW PINE, Valley, ID

Built 1997 Load: 47.2 t ADT: 70

WEISER RIVER ROAD

Good

Over: WEISER RIVER

1.5 N. 10.0 E. WEISER, Washington, ID

Built 1998 Load: 47.2 t ADT: 240

N 2400 E

Good

Over: ST. ANTHONY CANAL

1.2 N. 0.2 E. ST. ANTHONY, Fremont, ID

Built 2010 Load: 47.2 t ADT: 360

HARTLEY LANE

Good

Over: FARMERS UNION CANAL

E OF SH16;N OF BEACON LGT, Ada, ID

Built 2003 Load: 47.2 t ADT: 120

US 95 NBL

Good

Over: LAKE CREEK;NESS ROAD

8.0 N. WORLEY, Kootenai, ID

Built 2007 Load: 47.2 t ADT: 2,900

SH 28

Good

Over: LEMHI RIVER

16 N. LEADORE., Lemhi, ID

Built 2019 Load: 47.3 t ADT: 820

IDAHO ROAD

Good

Over: S. FORK ROCK CREEK

0.4 MI N OF E TRUAX RD, Benewah, ID

Built 2020 Load: 47.3 t ADT: 36

STC 7486;12TH ST

Good

Over: IDAHO CANAL

IN IDAHO FALLS;12TH ST, Bonneville, ID

Built 2020 Load: 47.3 t ADT: 4,100

SIOUX LANE

Good

Over: TOWER CREEK

5.85 N. 0.6 E. CARMEN, Lemhi, ID

Built 2015 Load: 47.6 t ADT: 30

SH 34

Good

Over: TINCUP CREEK

12.6 E. WAYAN, Caribou, ID

Built 2018 Load: 47.6 t ADT: 540

NO DATA ENTERED

Good

Over: GABE CREEK

NO DATA ENTERED, Idaho, ID

Built 2004 Load: 47.6 t ADT: 40

SMA 9183;TEN MILE

Good

Over: FIVE MILE CREEK

1.7 N. 2.0 W. MERIDIAN, Ada, ID

Built 2020 Load: 48.0 t ADT: 20,500

RIVER ROAD

Good

Over: DEEP CREEK

4.0 N. 2.5 W BUHL, Twin Falls, ID

Built 2018 Load: 48.0 t ADT: 130

MCCOY CREEK RD

Good

Over: JENSEN CREEK

12.1 S. 3.3 E. PALISADES, Bonneville, ID

Built 2016 Load: 48.0 t ADT: 50

FS ROUTE NO. 208

Good

Over: DOWNEY CREEK

13.4 MI FROM BABINS JCT., Shoshone, ID

Built 1974 Load: 48.0 t ADT: 40

FDR 595

Good

Over: BOULDER CREEK

31 MILES FROM POWELL R S, Clearwater, ID

Built 1974 Load: 48.0 t ADT: 30

SH 4

Good

Over: CANYON CREEK;TAMARACK BR

1.5 S. BURKE, Shoshone, ID

Built 2004 Load: 48.1 t ADT: 190

SH 21

Good

Over: MORES CR.;SPENCERS CABIN

10.5 S. IDAHO CITY, Boise, ID

Built 1995 Load: 48.1 t ADT: 2,800

US 95 SPUR

Good

Over: SNAKE RIVER; WEISER BR

IN WEISER, Washington, ID

Built 2010 Load: 48.1 t ADT: 3,800

US 91

Good

Over: BLACKFOOT CANAL

8.5 N. FORT HALL, Bingham, ID

Built 2004 Load: 48.1 t ADT: 4,700

SH 75

Good

Over: BIG WOOD RIVER

6.2 S. KETCHUM, Blaine, ID

Built 2002 Load: 48.1 t ADT: 14,000

FIRTH WAPELLO ROAD

Good

Over: SAND CREEK

1.4 S 1.3 E FIRTH, Bingham, ID

Built 2010 Load: 48.1 t ADT: 160

FLINT CREEK ROAD

Good

Over: JORDAN CREEK

38.4 W OREANA, Owyhee, ID

Built 2012 Load: 48.1 t ADT: 30

STC4710;GRAVES CRK

Good

Over: ROCK CREEK

9.7 S. 2.2 W. COTTONWOOD, Idaho, ID

Built 1998 Load: 48.1 t ADT: 30

US 95

Good

Over: LITTLE SALMON RIVER

13.9 N. NEW MEADOWS NCL, Adams, ID

Built 2019 Load: 48.3 t ADT: 3,000

STC4790;THORN CRK

Good

Over: THORN CREEK

3.4 N. 3.7 W. GENESSE, Latah, ID

Built 2013 Load: 48.3 t ADT: 320

LEMHI ROAD

Good

Over: CANYON CREEK

0.8 N. 0.2 E. LEADORE, Lemhi, ID

Built 2012 Load: 48.3 t ADT: 100

FS ROUTE NO. 208

Good

Over: YELLOW DOG CR

14 MI FROM BABINS JCT., Shoshone, ID

Built 1974 Load: 48.3 t ADT: 40

DAGGER FALLS ROAD

Good

Over: BEAR VALLEY CREEK

1 MI N. OF BRUCE MEADOWS, Valley, ID

Built 1981 Load: 48.3 t ADT: 50

NO DATA ENTERED

Good

Over: NO DATA ENTERED

NO DATA ENTERED, Camas, ID

Built 2001 Load: 48.3 t ADT: 50

N. KAY AVENUE

Good

Over: KUNA CANAL

0.8 E. 1.2 N. OF KUNA, Ada, ID

Built 2020 Load: 48.6 t ADT: 50

ABBOTT ROAD

Good

Over: OLD US 95/UPRR

0.6 W. 0.7 S. CHILCO, Kootenai, ID

Built 2013 Load: 48.6 t ADT: 3,100

SH 21

Good

Over: ELK CREEK

7.2 W. STANLEY, Custer, ID

Built 2022 Load: 48.6 t ADT: 560

2000 EAST ROAD

Good

Over: CEDAR DRAW CREEK

4.3 N. 2.1 W. FILER, Twin Falls, ID

Built 2012 Load: 48.9 t ADT: 240

SILVERSTONE WAY

Good

Over: FIVE MILE CREEK

MERIDIAN, Ada, ID

Built 2017 Load: 48.9 t ADT: 3,200

OWYHEE STORM AVE

Good

Over: FIVE MILE CREEK

NW MERIDIAN CL, Ada, ID

Built 2020 Load: 48.9 t ADT: 25

SIMPLOT CIRCLE

Good

Over: PORTER CANAL

IN IDAHO FALLS, Bonneville, ID

Built 2013 Load: 48.9 t ADT: 20

E. HYRUM DRIVE

Good

Over: SAND CREEK

4.5 N 0.2 E AMMON, Bonneville, ID

Built 2013 Load: 48.9 t ADT: 200

SH 25

Good

Over: A CANAL

1.3 E. RUPERT, Minidoka, ID

Built 2000 Load: 49.0 t ADT: 3,600

STC2822;GLENDALE R

Good

Over: BYPASS CANAL

2.7 S. 0.1 E. BELLEVUE, Blaine, ID

Built 1998 Load: 49.0 t ADT: 1,900

Showing 4,101-4,150 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.