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 6703; E 65TH S

Good

Over: WEST FORK SAND CREEK

2.0 S. 2.1 E. IDAHO FALLS, Bonneville, ID

Built 1973 Load: 26.3 t ADT: 3,800

S 50 W POLE LN RD

Good

Over: J CANAL

5.8 S 0.1 W BURLEY, Cassia, ID

Built 1990 Load: 26.3 t ADT: 230

100 SOUTH ROAD

Good

Over: N CANAL

1.0 S. 0.8 W. JEROME, Jerome, ID

Built 1995 Load: 26.3 t ADT: 1,300

STC3780;W GALLOWAY

Good

Over: NOTUS CANAL

1.7 N. 2.4 E. NOTUS, Canyon, ID

Built 1969 Load: 26.3 t ADT: 350

STC 4786;JOHNSON

Good

Over: OROFINO CREEK

IN OROFINO;JOHNSON AVE., Clearwater, ID

Built 1978 Load: 26.3 t ADT: 1,900

CROOKED RIVER ROAD

Good

Over: CROOKED RIVER

6.0 S. 4.0 W. ELK CITY, Idaho, ID

Built 1965 Load: 26.3 t ADT: 110

W ANTELOPE;FR 137

Good

Over: ANTELOPE CREEK

1.0 N. 19.5 W. ARCO, Butte, ID

Built 1966 Load: 26.3 t ADT: 10

CHALLIS CREEK RD

Good

Over: CHALLIS CREEK

3.8 N. 1.8 W. CHALLIS, Custer, ID

Built 1997 Load: 26.3 t ADT: 470

HOUSTON RD

Good

Over: BIG LOST RIVER

0.5 S. LESLIE, Custer, ID

Built 1992 Load: 26.3 t ADT: 100

N. BAKER ROAD

Good

Over: LEMHI RIVER (BAKER BR)

5.5 S. 8.6 E. SALMON, Lemhi, ID

Built 1977 Load: 26.3 t ADT: 150

17 MILE LANE

Good

Over: LEMHI RIVER;17 MILE BR

4.7 N. 0.7 W. TENDOY, Lemhi, ID

Built 1977 Load: 26.3 t ADT: 190

W. CAMAS CREEK RD

Good

Over: BEAVER CREEK

3.42 N SPENCER, Clark, ID

Built 1970 Load: 26.3 t ADT: 110

NO DATA ENTERED

Good

Over: LOLO CREEK

WHITE CREEK, Idaho, ID

Built 1987 Load: 26.6 t ADT: 150

FDR 568

Good

Over: EAST FORK LEGENDARY BEAR

RD. 568 MP 3.20, Idaho, ID

Built 2003 Load: 26.6 t ADT: 5

NO DATA ENTERED

Good

Over: MANN CREEK

NO DATA ENTERED, Washington, ID

Built 1976 Load: 26.6 t ADT: 50

ROAD

Good

Over: ROCK CREEK

NO DATA ENTERED, Fremont, ID

Built 1980 Load: 26.6 t ADT: 50

STC 7834;LINE ST

Good

Over: PARADISE CREEK

IN MOSCOW @ U OF I, Latah, ID

Built 2010 Load: 26.9 t ADT: 4,300

BOTTLE BAY ROAD

Good

Over: BIKE/PEDESTRIAN UP

2.5 S. 0.01 E. SANDPOINT, Bonner, ID

Built 2018 Load: 26.9 t ADT: 2,700

1920: DARLING CREE

Good

Over: West Fork Morgan Creek

6.5 mi NW of US93, Custer, ID

Built 1995 Load: 26.9 t ADT: 25

E 800 N

Good

Over: CROSSCUT CANAL

0.1 N. 0.8 W. CHESTER, Fremont, ID

Built 1990 Load: 27.0 t ADT: 80

US 20 EBL

Good

Over: STP 7726;S.REXBURG IC

1.5 S. REXBURG, Madison, ID

Built 1981 Load: 27.2 t ADT: 15,500

US 20 WBL

Good

Over: STP 7726;S.REXBURG IC

1.5 S. REXBURG, Madison, ID

Built 1981 Load: 27.2 t ADT: 15,500

US 20 EBL

Good

Over: SH 33;REXBURG IC

0.5 W. REXBURG;SH 33, Madison, ID

Built 1981 Load: 27.2 t ADT: 11,750

LICK CREEK ROAD

Good

Over: N. FK. LICK CREEK

14.5 E 10.5 N MCCALL, Valley, ID

Built 2009 Load: 27.2 t ADT: 40

STC 4706;WARREN RD

Good

Over: SUMMIT CREEK

1.9 S. 0.5 E. BURGDORF, Idaho, ID

Built 1975 Load: 27.2 t ADT: 110

STC4783;DENT BR RD

Good

Over: ELK CREEK

1.5 S. 0.4 E. ELK RIVER, Clearwater, ID

Built 2003 Load: 27.2 t ADT: 180

STC 6774;TETON HWY

Good

Over: N.FK.TETON RIVER

0.7 N. TETON, Fremont, ID

Built 1977 Load: 27.2 t ADT: 1,200

BUTTE ROAD

Good

Over: SAND CREEK

1.8 N. 1.0 W. GOSHEN, Bingham, ID

Built 1996 Load: 27.2 t ADT: 150

BLACKFOOT RIVER RD

Good

Over: BLACKFOOT RIVER

11.4N 2.5E SODA SPRINGS, Caribou, ID

Built 1980 Load: 27.2 t ADT: 600

2300 EAST ROAD

Good

Over: SALMON CANAL LATERAL #2

0.7 N. 1.0 W. HOLLISTER, Twin Falls, ID

Built 1983 Load: 27.2 t ADT: 20

TOWN CIRCLE ROAD

Good

Over: SEBREE CANAL

2.7 S. 5.4 E. NOTUS, Canyon, ID

Built 1980 Load: 27.2 t ADT: 400

HANSEN LANE

Good

Over: GOLD FORK CREEK

3.0 S. 3.6 E. DONNELLY, Valley, ID

Built 1987 Load: 27.2 t ADT: 20

N. CRANE ROAD

Good

Over: GRANGER CREEK

3.5 S. 11.8 E. MIDVALE, Washington, ID

Built 1996 Load: 27.2 t ADT: 60

STC4805;CEDR RDG R

Good

Over: CEDAR CREEK

5.2 E. 2.5 N. KENDRICK, Latah, ID

Built 1978 Load: 27.2 t ADT: 310

TELFORD RD;49TH N

Good

Over: SAND CREEK

3.4 N. 6.3 E. IDAHO FALLS, Bonneville, ID

Built 1977 Load: 27.2 t ADT: 2,200

N 5TH W

Good

Over: BURGESS CANAL

2.1 N. 4.0 W. UCON, Bonneville, ID

Built 1962 Load: 27.2 t ADT: 660

E 500 N

Good

Over: S. BRANCH FALL RIVER CNL

0.3 S. 3.6 E. ST. ANTHONY, Fremont, ID

Built 1997 Load: 27.2 t ADT: 120

NO DATA ENTERED

Good

Over: INDIAN CREEK

NO DATA ENTERED, Idaho, ID

Built 2011 Load: 27.2 t ADT: 100

FS ROUTE NO. 1347

Good

Over: FEDAR CREEK

FEDAR CREEK, Bonner, ID

Built 2010 Load: 27.2 t ADT: 40

FS ROUTE NO. 218

Good

Over: SIMMONS CREEK

1 MI F/JCT FS RT 218 & 50, Shoshone, ID

Built 1935 Load: 27.2 t ADT: 50

FS ROUTE 509

Good

Over: EAST FORK BLUFF CREEK

EAST FORK BLUFF CREEK, Shoshone, ID

Built 2006 Load: 27.2 t ADT: 40

HELLROARING RIDGE

Good

Over: HELLROARING CREEK

HELLROARING CREEK XING, Boundary, ID

Built 2017 Load: 27.2 t ADT: 50

FS ROUTE NO. 1341

Good

Over: NO DATA ENTERED

BEAVER CREEK, Bonner, ID

Built 2007 Load: 27.2 t ADT: 40

ROUGH CREEK ROAD

Good

Over: MORES CREEK

8.5 MI NE IDAHO CITY, Boise, ID

Built 1979 Load: 27.2 t ADT: 25

SMA 7143;USTICK RD

Good

Over: NORTH SLOUGH

IN BOISE, Ada, ID

Built 2014 Load: 27.5 t ADT: 16,000

FS ROUTE NO. 3325

Good

Over: GLOVER CREEK

GLOVER CREEK, Shoshone, ID

Built 1978 Load: 27.5 t ADT: 40

FOREST ROUTE 311

Good

Over: BIG CREEK

BIG CREEK DRAINAGE, Idaho, ID

Built 2019 Load: 27.5 t ADT: 50

W. WILLOW-BIG OWL

Good

Over: CROOKED RIVER

2 MI E. OF EDNA CREEK CG, Boise, ID

Built 1971 Load: 27.5 t ADT: 15

CLEAR CREEK ROAD

Good

Over: STONEY MEADOW CREEK

14 MI SW OF WARM LAKE, Valley, ID

Built 1963 Load: 27.5 t ADT: 12

OKEEFE CREEK ROAD

Good

Over: CLEAR CREEK

9 MI NNE OF LOWMAN ID, Boise, ID

Built 1966 Load: 27.5 t ADT: 10

Showing 3,201-3,250 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.