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

STC6770;SALEM RD

Good

Over: HENRYS FORK SNAKE RIVER

2.1 S 1.0 W PARKER, Fremont, ID

Built 2007 Load: 52.6 t ADT: 2,800

1700 EAST RD

Good

Over: LOW LINE CANAL

2.3 S. 2.5 E. BUHL, Twin Falls, ID

Built 2003 Load: 52.6 t ADT: 400

BAUMGARTNER RD

Good

Over: FEATHER RIVER

0.2 N FEATHERVILLE, Elmore, ID

Built 2010 Load: 52.6 t ADT: 10

STC 4719;DIXIE Rd

Good

Over: TRAPPER CREEK

10.8 S. 4.4 E. ELK CITY, Idaho, ID

Built 1965 Load: 52.6 t ADT: 110

ECHANOVE RD

Good

Over: CURRANT CREEK

IN BOISE;HIDDEN SPRINGS, Ada, ID

Built 2002 Load: 52.6 t ADT: 99

US 95

Good

Over: LITTLE SALMON RIVER

0.2 W. NEW MEADOWS WCL, Adams, ID

Built 2021 Load: 52.8 t ADT: 3,700

US 30

Good

Over: GEORGETOWN CREEK

IN GEORGETOWN, Bear Lake, ID

Built 2016 Load: 53.1 t ADT: 3,400

300 N ROAD

Good

Over: S CANAL

3 N. 0.7 E. JEROME, Jerome, ID

Built 2017 Load: 53.1 t ADT: 190

STC 3874;STAFFORD

Good

Over: NOTUS CANAL

1.2 N. 2.4 E. NOTUS, Canyon, ID

Built 2022 Load: 53.1 t ADT: 230

EVENT CENTER DRIVE

Good

Over: SIDEHILL CANAL

IN IDAHO FALLS, Bonneville, ID

Built 2019 Load: 53.1 t ADT: 500

SH 46

Good

Over: LATERAL W-9 CANAL

0.9 S WENDELL SCL, Gooding, ID

Built 2016 Load: 53.1 t ADT: 3,500

SH 13

Good

Over: M.FK.CLEARWATER RIVER

KOOSKIA NWCL, Idaho, ID

Built 1994 Load: 53.5 t ADT: 2,900

STC 3811; FH61 RD

Good

Over: S FK BOISE RVR (PINE BR)

0.3 S PINE, Elmore, ID

Built 2018 Load: 53.5 t ADT: 580

SMA7013;CLOVERDALE

Good

Over: I 84;CLOVERDALE RD GS

6.5 W. BOISE, Ada, ID

Built 2019 Load: 53.5 t ADT: 19,000

STP7933;FRANKLIN R

Good

Over: NOTUS CANAL

IN CALDWELL;FRANKLIN RD, Canyon, ID

Built 2009 Load: 53.5 t ADT: 21,000

STC 8743;7TH AVE N

Good

Over: LOWER PAYETTE DITCH

IN PAYETTE;7TH AVE N, Payette, ID

Built 2009 Load: 53.5 t ADT: 2,200

MIDDLE FORK ROAD

Good

Over: M.FK.WEISER RIVER

4.3 S. 2.0 W. COUNCIL, Adams, ID

Built 1977 Load: 53.5 t ADT: 10

FRUITVALE ROAD

Good

Over: WEISER RIVER

2.9 S. 2.7 W. EVERGREEN, Adams, ID

Built 2000 Load: 53.5 t ADT: 80

BOISE STREET

Good

Over: POWER CANAL

HORSESHOE BEND, Boise, ID

Built 1995 Load: 53.5 t ADT: 60

GRIMES PASS ROAD

Good

Over: GRIMES CREEK

4.9S. 5.5E. GARDEN VALLEY, Boise, ID

Built 1996 Load: 53.5 t ADT: 20

STC 8202;W 9TH ST

Good

Over: GALLOWAY CANAL

0.56 N 0.71 W WEISER, Washington, ID

Built 2021 Load: 53.5 t ADT: 280

US 26B

Good

Over: ENTERPRIZE CANAL

0.5 SW RIRIE, Bonneville, ID

Built 2015 Load: 53.8 t ADT: 1,600

SMA7190;SUBSTATION

Good

Over: LAST CHANCE CANAL

0.4 S 1.2 E EMMETT, Gem, ID

Built 2016 Load: 54.1 t ADT: 6,600

I 15B;MERRILL ROAD

Good

Over: I 15;N. MCCAMMON IC

1.5 N. MCCAMMON, Bannock, ID

Built 2012 Load: 54.4 t ADT: 5,200

SH 33

Good

Over: MOOSE CREEK

3.6 E. VICTOR, Teton, ID

Built 2010 Load: 54.4 t ADT: 7,200

I 84

Good

Over: SH 21;GOWEN RD IC

BOISE SCL, Ada, ID

Built 2015 Load: 54.4 t ADT: 50,000

US 95

Good

Over: LESTER CREEK

2.0 S. COUNCIL, Adams, ID

Built 2017 Load: 54.4 t ADT: 2,900

MYERS STREET

Good

Over: LOGGERS CREEK

IN BOISE;MYERS ST., Ada, ID

Built 1972 Load: 54.4 t ADT: 200

SMA 7403;FRANKLIN

Good

Over: TEN MILE CREEK

0.5 S. 2.0 W. MERIDIAN, Ada, ID

Built 1990 Load: 54.4 t ADT: 13,000

STC7158;COMMERCIAL

Good

Over: NOTUS CANAL

IN CALDWELL;COMMERCIAL WY, Canyon, ID

Built 2010 Load: 54.4 t ADT: 1,400

MORENO DRIVE

Good

Over: DEER FLAT CALDWELL CANAL

0.4 E 3.6 S CALDWELL, Canyon, ID

Built 2006 Load: 54.4 t ADT: 200

US 91

Good

Over: CEDAR POINT CANAL

2.5 NE FIRTH, Bingham, ID

Built 2004 Load: 54.8 t ADT: 3,600

FDR 255

Good

Over: NF CLEARWATER RIVER

KELLY FORKS BRIDGE, Clearwater, ID

Built 1968 Load: 54.8 t ADT: 80

RAMMAGE MEADOWS RD

Good

Over: SEC.FK.CHIEF EAGLE EYE

4 MI W SAGEN RESERVOIR, Gem, ID

Built 1990 Load: 54.8 t ADT: 20

SH 3

Good

Over: ST MARIES RR

IN ST MARIES, Benewah, ID

Built 2019 Load: 55.1 t ADT: 4,600

SMA7217;S. VALLEY

Good

Over: AMI TRAIL

0.3 W. of I15 IC, Bannock, ID

Built 2016 Load: 55.1 t ADT: 5,200

OLYMPUS DR

Good

Over: FUTURE PED UNDERPASS

POCATELLO, Bannock, ID

Built 2018 Load: 55.1 t ADT: 6,500

SH 75

Good

Over: BIG WOOD RIVER

7.8 N. KETCHUM, Blaine, ID

Built 1991 Load: 55.3 t ADT: 1,500

ELEVATOR LOOP RD

Good

Over: BANNOCK CREEK

6.4N 11.3E AMERICAN FALLS, Power, ID

Built 2008 Load: 55.3 t ADT: 40

PRIEST ROAD

Good

Over: SILVER CREEK;S.E. PICABO

2.3 S. 2.7 E. PICABO, Blaine, ID

Built 1995 Load: 55.3 t ADT: 30

FIR GROVE ROAD

Good

Over: CAMAS CREEK

3.6 S. 2.3 E. FAIRFIELD, Camas, ID

Built 1986 Load: 55.3 t ADT: 30

SMA9773;LINDER RD

Good

Over: RIDENBAUGH CANAL

2.2 S. 1.1 W. MERIDIAN, Ada, ID

Built 1992 Load: 55.3 t ADT: 4,600

STC8533;SMITH AVE

Good

Over: PHYLLIS CANAL

0.3 N 3.2 W NAMPA, Canyon, ID

Built 2010 Load: 55.3 t ADT: 590

WEISER RIVER ROAD

Good

Over: GALLOWAY CANAL

0.2 S. 5.8 E. WEISER, Washington, ID

Built 2005 Load: 55.3 t ADT: 240

SMA7606:BOWN WAY

Good

Over: RIDENBAUGH CANAL

IN BOISE, Ada, ID

Built 2004 Load: 55.3 t ADT: 5,200

EVENT CENTER DRIVE

Good

Over: PORTER CANAL

IN IDAHO FALLS, Bonneville, ID

Built 2019 Load: 55.7 t ADT: 500

W. 6TH STREET

Good

Over: LITTLE BEAR CREEK

IN TROY, Latah, ID

Built 2020 Load: 55.7 t ADT: 50

S WAYFINDER AVE

Good

Over: TEN MILE CREEK

1.8 W MERIDIAN, Ada, ID

Built 2019 Load: 56.1 t ADT: 1,000

SH 74

Good

Over: ROCK CREEK

IN TWIN FALLS, Twin Falls, ID

Built 1993 Load: 56.2 t ADT: 18,000

SMA 3789;BOGUS

Good

Over: MAIN FORK STUART GULCH

BOISE;BOGUS BASIN ROAD, Ada, ID

Built 1998 Load: 56.2 t ADT: 790

Showing 4,201-4,250 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.