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

STC 3838;PLAZA RD

Fair

Over: PAYETTE RIVER;PLAZA BR.

3.3 N. 2.8 E. EMMETT, Gem, ID

Built 1959 Load: 27.2 t ADT: 950

FARM TO MARKET RD

Fair

Over: HOG CREEK

4.0 S. 9.1 E. MIDVALE, Washington, ID

Built 1966 Load: 27.2 t ADT: 50

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

STC 6760;W4000N

Fair

Over: N.FK.SNAKE R.;HIBBARD BR

3.0 W. 4.2 N. REXBURG, Madison, ID

Built 1968 Load: 27.2 t ADT: 850

STC 6770; N SALEM

Fair

Over: N.FK.TETON RIVER

4.8 N. 0.6 E. REXBURG, Madison, ID

Built 1976 Load: 27.2 t ADT: 4,100

SMA 7166;1ST ST

Fair

Over: IDAHO CANAL

IN IDAHO FALLS;1ST ST., Bonneville, ID

Built 1980 Load: 27.2 t ADT: 17,000

STC7301;FREMONT ST

Fair

Over: PORTNEUF RIVER

IN POCATELLO;FREMONT ST., Bannock, ID

Built 1968 Load: 27.2 t ADT: 2,300

SMA8353;16TH AVE

Fair

Over: UPRR;1ST ST N

IN NAMPA;16TH AVE, Canyon, ID

Built 1969 Load: 27.2 t ADT: 20,000

BOWMAN ROAD

Fair

Over: I 15 NB-SB;BOWMAN RD.GS

7.2 S. ARIMO, Bannock, ID

Built 1971 Load: 27.2 t ADT: 100

MCDONALD ROAD

Fair

Over: ABERDEEN SPRINGFILED CNL

2.8 N. 0.2 W. GROVELAND, Bingham, ID

Built 2004 Load: 27.2 t ADT: 300

GAMBLE 2200 S

Fair

Over: HIGH LINE CANAL

4.0 S. 1.75 W. ABERDEEN, Bingham, ID

Built 1987 Load: 27.2 t ADT: 30

E. 100 S.

Fair

Over: MARSH CREEK

0.2 S. 2.4 E. DECLO, Cassia, ID

Built 1999 Load: 27.2 t ADT: 100

1050 SOUTH ROAD

Fair

Over: CLOVER CREEK

8.5 N. 1.5 E. BLISS, Gooding, ID

Built 1977 Load: 27.2 t ADT: 30

1775 SOUTH ROAD

Fair

Over: LITTLE WOOD RIVER

0.3 N. 4.3 E. GOODING, Gooding, ID

Built 1926 Load: 27.2 t ADT: 780

SMA3909;KUNA MORA

Fair

Over: BLACKS CREEK

10.6 S. 5.5 E. BOISE, Ada, ID

Built 1968 Load: 27.2 t ADT: 1,300

STC 3883;ROBIE CRK

Fair

Over: MORES CREEK

13.6 S. 8.1 W. IDAHO CITY, Boise, ID

Built 1997 Load: 27.2 t ADT: 300

GREEN ROAD

Fair

Over: FARMERS COOP SEBREE CNL

2.4 S. 5.1 E. NOTUS, Canyon, ID

Built 1939 Load: 27.2 t ADT: 50

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

RIVER ROAD

Fair

Over: GRAND VIEW IRRG.DIST.CNL

3.1 S. 5.6 E. GRAND VIEW, Owyhee, ID

Built 1965 Load: 27.2 t ADT: 220

WARD ROAD SOUTH

Fair

Over: RUSH CREEK

5.6 N. 0.5 W. CAMBRIDGE, Washington, ID

Built 1987 Load: 27.2 t ADT: 30

MCKENZIE CREEK RD.

Fair

Over: SLIPPY CREEK

1.7 N. SLATE CREEK R.STA, Idaho, ID

Built 1923 Load: 27.2 t ADT: 40

CENTER CREEK ROAD

Fair

Over: RICE CREEK

11.5 S. 2.8 W. COTTONWOOD, Idaho, ID

Built 1960 Load: 27.2 t ADT: 140

OREILLY ROAD

Fair

Over: PALOUSE RIVER

1.7 W. HARVARD, Latah, ID

Built 1980 Load: 27.2 t ADT: 30

SCOVILLE ROAD

Fair

Over: DEEP CREEK

1.7 N. 1.6 W. POTLATCH, Latah, ID

Built 1965 Load: 27.2 t ADT: 30

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

W 49TH NORTH

Fair

Over: GREAT WESTERN CANAL

3.4 N. 2.3 W. IDAHO FALLS, Bonneville, ID

Built 1960 Load: 27.2 t ADT: 300

SMA6734;S 35TH W

Fair

Over: PORTER CANAL

1.5 S. 3.2 W. IDAHO FALLS, Bonneville, ID

Built 1952 Load: 27.2 t ADT: 1,300

STC 6749; 3300W

Fair

Over: BIG LOST RIVER

1.5 N. 2.3 W. ARCO, Butte, ID

Built 1926 Load: 27.2 t ADT: 270

STC 6749; 2900N

Fair

Over: BIG LOST RIVER

2.7 S. 0.2 E. MOORE, Butte, ID

Built 1926 Load: 27.2 t ADT: 160

4525 E

Fair

Over: FALL RIVER

0.2 S. 8.4 E. MARYSVILLE, Fremont, ID

Built 1983 Load: 27.2 t ADT: 180

S6810;PACKSADDLE R

Fair

Over: TETON RIVER(CACHE BR)

2.1 S. 2.5 W. TETONIA, Teton, ID

Built 1956 Load: 27.2 t ADT: 250

COPPER BASIN LOOP

Fair

Over: STAR HOPE CREEK

21.0 E. SUN VALLEY, Custer, ID

Built 1970 Load: 27.2 t ADT: 20

FS ROUTE NO. 413

Fair

Over: COPPER CREEK

COPPER CREEK, Kootenai, ID

Built 1975 Load: 27.2 t ADT: 50

FOREST ROAD 309

Fair

Over: MILL CREEK

1 MI. FROM STATE HWY 14, Idaho, ID

Built 1966 Load: 27.2 t ADT: 30

BEAVER-LOON ROAD

Fair

Over: W.FK MAYFIELD CREEK

19 MILES N OF SUNBEAM, Custer, ID

Built 1968 Load: 27.2 t ADT: 10

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

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

1320 NORTH ROAD

Fair

Over: EAST MAIN CANAL

5.5 N. 0.9 W. RICHFIELD, Lincoln, ID

Built 1950 Load: 27.9 t ADT: 50

STC 5784;PACK RVR

Fair

Over: PACK RIVER

3.5 N. 2.7 W. SAMUELS, Bonner, ID

Built 1982 Load: 27.9 t ADT: 470

S BULL RUN ROAD

Fair

Over: CDA RIVER;ROSE LAKE BR

2.5 S. 1.5 W.ROSE LAKE IC, Kootenai, ID

Built 1983 Load: 27.9 t ADT: 40

N 1600 E

Fair

Over: EGIN CANAL

0.3 S. EGIN, Fremont, ID

Built 1978 Load: 27.9 t ADT: 30

4500 EAST

Fair

Over: HARRISON CANAL

0.9 N. 1.4 W. RIRIE, Jefferson, ID

Built 1971 Load: 27.9 t ADT: 70

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 CR

NO DATA ENTERED, Idaho, ID

Built 1964 Load: 27.9 t ADT: 10

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

NO DATA ENTERED

Fair

Over: WALTON CREEK

ELK SUMMIT ROAD 362, Idaho, ID

Built 1953 Load: 27.9 t ADT: 20

DOLLAR CREEK ROAD

Fair

Over: DOLLAR CK

5 MI N. OF WARM LAKE, Valley, ID

Built 1976 Load: 27.9 t ADT: 10

Showing 1,301-1,350 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.