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

I 184;W FAIRVIEW

Fair

Over: SETTLERS CANAL

IN BOISE, Ada, ID

Built 1967 Load: 45.4 t ADT: 54,500

STC 3750;MIDDLETON

Fair

Over: FIFTEEN MILE CREEK

0.8 S. 0.3 E. MIDDLETON, Canyon, ID

Built 2004 Load: 45.4 t ADT: 16,000

STC 5783;PENINSULA

Fair

Over: PRIEST R.;MC ABEE FALLS

7.2N. 1.7E. PRIEST RIVER, Bonner, ID

Built 1961 Load: 45.4 t ADT: 750

MASSACRE ROCKS RD

Fair

Over: I 86;MASSACRE ROCKS IC

10.9 W. AMERICAN FALLS, Power, ID

Built 1985 Load: 45.4 t ADT: 110

OLD HORNET ROAD

Fair

Over: HORNET CREEK

1.2 N. 2.2 W. COUNCIL, Adams, ID

Built 1971 Load: 45.4 t ADT: 100

STC 4718;SELWAY RD

Fair

Over: LOCHSA RIVER(LOWELL BR)

0.1 N. 18.2 E. KOOSKIA, Idaho, ID

Built 1960 Load: 45.4 t ADT: 180

STC 5788;RIVER RD

Fair

Over: CLARK FORK RIVER

0.6 S. 0.3 W. CLARK FORK, Bonner, ID

Built 2004 Load: 45.4 t ADT: 790

FS ROUTE NO. 151

Fair

Over: FALLS CREEK

FALLS CREEK, Shoshone, ID

Built 1974 Load: 45.4 t ADT: 40

FS ROUTE NO. 320

Fair

Over: RED IVES CREEK

RED IVES CREEK, Shoshone, ID

Built 1964 Load: 45.4 t ADT: 50

SMA7406;PANCHERI

Fair

Over: EAST LATERAL CANAL

IN IDAHO FALLS, Bonneville, ID

Built 2014 Load: 46.0 t ADT: 4,200

N CRANE ROAD

Fair

Over: CRANE CREEK

5.2 S. 14.5 E. MIDVALE, Washington, ID

Built 2015 Load: 46.0 t ADT: 50

STC 7023;EDGEWOOD

Fair

Over: DRY CREEK CANAL

0.1N 1.2E Eagle, Ada, ID

Built 2015 Load: 46.0 t ADT: 2,400

US 12

Fair

Over: CLEARWATER R.(KAMIAH BR)

IN KAMIAH, Lewis, ID

Built 1998 Load: 46.3 t ADT: 5,900

I 86 EBL

Fair

Over: HILINE ROAD GS

0.8 E. CHUBBUCK, Bannock, ID

Built 2009 Load: 46.3 t ADT: 12,750

I 15 SBL

Fair

Over: BEAVER CREEK

5.0 N. HAMER, Jefferson, ID

Built 1989 Load: 46.3 t ADT: 1,700

US 20 WBL & EBL

Fair

Over: SMA 9083;27TH STREET

IN BOISE;BOISE CONNECTOR, Ada, ID

Built 1990 Load: 46.3 t ADT: 36,500

US 26

Fair

Over: RAINY CREEK

IN SWAN VALLEY, Bonneville, ID

Built 1992 Load: 46.3 t ADT: 5,200

SH 39 SBL

Fair

Over: SNAKE R.;AM.FALLS BR.

0.7 W. AMERICAN FALLS, Power, ID

Built 1975 Load: 46.3 t ADT: 1,350

SH 41

Fair

Over: BURLINGTON NORTHERN RR

0.3 N. RATHDRUM, Kootenai, ID

Built 2014 Load: 46.3 t ADT: 14,000

SH 69

Fair

Over: TEN MILE CREEK

1.0 S. MERIDIAN, Ada, ID

Built 1963 Load: 46.3 t ADT: 47,000

I 84 EBL

Fair

Over: SAND HOLLOW CREEK

8.3 W. CALDWELL, Canyon, ID

Built 1962 Load: 46.3 t ADT: 15,250

I 90B LOOP

Fair

Over: SOUTH FORK CDA RIVER

IN WALLACE, Shoshone, ID

Built 1987 Load: 46.3 t ADT: 2,200

US 95

Fair

Over: LITTLE SALMON RIVER

10.8 N. NEW MEADOWS NCL, Idaho, ID

Built 1975 Load: 46.3 t ADT: 3,000

COUNTY ROAD

Fair

Over: I 15;W.PORTERVILLE RD.GS

2.2 N. BLACKFOOT, Bingham, ID

Built 1962 Load: 46.3 t ADT: 1,400

1010 SOUTH ROAD

Fair

Over: MILNER GOODING CANAL

1.5 S. 5.3 E. HAZELTON, Jerome, ID

Built 1966 Load: 46.3 t ADT: 550

POWER LINE ROAD

Fair

Over: MORA CANAL

9.5 S. 0.5 E. NAMPA, Canyon, ID

Built 1987 Load: 46.3 t ADT: 140

SMA7605:SELTICE WY

Fair

Over: SELTICE WAY PED OP

AT COEUR DALENE WCL, Kootenai, ID

Built 2007 Load: 46.3 t ADT: 14,000

OLD DOLLAR ROAD

Fair

Over: TRAIL CREEK

IN SUN VALLEY, Blaine, ID

Built 2004 Load: 46.3 t ADT: 1,000

STC6859;E RIRIE HY

Fair

Over: EAGLE ROCK CANAL

AT RIRIE, Bonneville, ID

Built 2015 Load: 46.7 t ADT: 630

STC6859;E RIRIE HY

Fair

Over: ANDERSON CANAL

AT RIRIE, Bonneville, ID

Built 2015 Load: 46.7 t ADT: 630

NO DATA ENTERED

Fair

Over: COLD SPRINGS CREEK

40 MI FROM PIERCE ID, Clearwater, ID

Built 1949 Load: 46.7 t ADT: 100

FDR 1649

Fair

Over: BOULDER CREEK

WILDERNESS GATEWAY, Idaho, ID

Built 1968 Load: 46.7 t ADT: 30

FS ROUTE NO. 812

Fair

Over: TEPEE CREEK

AT TEPEE CR, Shoshone, ID

Built 1957 Load: 47.0 t ADT: 50

FDR 250

Fair

Over: NF CLEARWATER RIVER

BUNGALOW BRIDGE, Clearwater, ID

Built 1958 Load: 47.0 t ADT: 100

SH 3

Fair

Over: ROSE LAKE OVERPASS

3.1 S. ROSE LAKE, Kootenai, ID

Built 1997 Load: 47.2 t ADT: 1,900

SH 24

Fair

Over: B CANAL

0.4 E. RUPERT, Minidoka, ID

Built 1983 Load: 47.2 t ADT: 3,500

I 84

Fair

Over: C CANAL

19.3 W. BURLEY, Jerome, ID

Built 1966 Load: 47.2 t ADT: 23,500

US 93

Fair

Over: LOW LINE CANAL

39.7 N. NEVADA LINE, Twin Falls, ID

Built 1994 Load: 47.2 t ADT: 6,900

SMA 7155;GOVT WAY

Fair

Over: I 90 EB-WB; GOVT WAY GS

IN COEUR D ALENE, Kootenai, ID

Built 2006 Load: 47.2 t ADT: 18,000

COTTONWOOD ROAD

Fair

Over: COTTONWOOD CREEK

10.0 E. 2.0 N DOWNEY, Bannock, ID

Built 1975 Load: 47.2 t ADT: 10

1600 EAST RD

Fair

Over: LOW LINE CANAL

1.6 S. 1.4 E. BUHL, Twin Falls, ID

Built 1994 Load: 47.2 t ADT: 60

BARTLETT ROAD

Fair

Over: LITTLE HANGMAN CREEK

1.9 N. 1.2 E. TILMA, Benewah, ID

Built 2004 Load: 47.2 t ADT: 30

US 95

Fair

Over: US 95NB OFF R;SAND CREEK

IN SANDPOINT, Bonner, ID

Built 2012 Load: 47.2 t ADT: 12,500

FDR

Fair

Over: SKELETON CREEK

ELMORE-CAMAS COUNTY LINE, Camas, ID

Built 1955 Load: 47.2 t ADT: 50

SH 81

Fair

Over: MARSH CREEK

IN DECLO ECL, Cassia, ID

Built 2013 Load: 47.3 t ADT: 2,500

US 95

Fair

Over: WEISER RIVER

IN WEISER SCL, Washington, ID

Built 2013 Load: 47.3 t ADT: 8,600

STP7605;SELTICE WY

Fair

Over: I 90 EB-WB;SELTICE IC

AT POST FALLS WCL, Kootenai, ID

Built 1977 Load: 47.3 t ADT: 17,500

BIG CREEK ROAD

Fair

Over: BIG CREEK

4.5 S. BIG CREEK, Valley, ID

Built 2016 Load: 47.6 t ADT: 10

NO DATA ENTERED

Fair

Over: NF CLEARWATER RIVER

WASHINGTON CREEK BRIDGE, Clearwater, ID

Built 1962 Load: 47.6 t ADT: 20

I 15 SBL

Fair

Over: SNAKE RIVER;BLACKFOOT BR

1.9 N. BLACKFOOT, Bingham, ID

Built 2002 Load: 48.1 t ADT: 12,750

Showing 2,751-2,800 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.