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

CREEKSIDE MEADOWS

Good

Over: TETON CREEK

IN DRIGGS, Teton, ID

Built 2004 Load: 20.0 t ADT: 70

STIBNITE ROAD

Good

Over: SALT CREEK

1.4 S. 6.7 E. YELLOW PINE, Valley, ID

Built 2010 Load: 20.1 t ADT: 30

NO DATA ENTERED

Good

Over: SELWAY RIVER

NO DATA ENTERED, Idaho, ID

Built 1935 Load: 20.1 t ADT: 10

FS ROUTE NO. 760

Good

Over: LITTLE NF CLEARWATER

LITTLE NF CLEARWATER, Shoshone, ID

Built 2006 Load: 20.4 t ADT: 50

SILVER CREEK PLUNG

Good

Over: SILVER CREEK

SILVER CREEK PLUNGE CG, Valley, ID

Built 2005 Load: 20.4 t ADT: 50

FDR

Good

Over: FISHHOOK CREEK

REDFISH LAKE, Custer, ID

Built 1975 Load: 20.4 t ADT: 50

FDR

Good

Over: LITTLE SMOKY CREEK

18 MILES NORTH FAIRFIELD, Camas, ID

Built 1959 Load: 20.4 t ADT: 50

STC3768;HUBBARD

Good

Over: NEW YORK CANAL

1.8 N 5.1 E KUNA, Ada, ID

Built 2013 Load: 20.7 t ADT: 1,200

FS ROUTE NO. 326

Good

Over: LOOP CREEK

LOOP CR, Shoshone, ID

Built 1999 Load: 20.7 t ADT: 40

FDR

Good

Over: BIG SMOKY CREEK

BIG SMOKY JCT, Camas, ID

Built 1977 Load: 20.7 t ADT: 50

US 20B;BRIDGE ST

Good

Over: US 20;ST. ANTHONY IC

IN ST ANTHONY, Fremont, ID

Built 1984 Load: 20.9 t ADT: 8,200

US 93

Good

Over: ARCO CANAL

1.0 N. ARCO, Butte, ID

Built 1962 Load: 20.9 t ADT: 2,400

STC 6774;N 2400 E

Good

Over: TWIN GROVES CANAL

0.7 S. 0.2 E. ST. ANTHONY, Fremont, ID

Built 1980 Load: 20.9 t ADT: 2,000

COTTONWOOD ROAD

Good

Over: CORBETT SLOUGH CANAL

0.6 S. 2.0 W. WAPELLO, Bingham, ID

Built 1965 Load: 20.9 t ADT: 100

W 113TH S

Good

Over: E. BRANCH SAND CREEK

1.0 N. 0.3 W. TAYLORVILLE, Bonneville, ID

Built 1999 Load: 20.9 t ADT: 780

E. ROH LANE

Good

Over: ANDERSON CANAL

1.4 S. UCON, Bonneville, ID

Built 2004 Load: 20.9 t ADT: 50

N 4525 E

Good

Over: MARYSVILLE CANAL

8.4 E. MARYSVILLE, Fremont, ID

Built 1991 Load: 20.9 t ADT: 180

2ND EAST STREET

Good

Over: EAGLE ROCK CANAL

IN RIRIE;2ND E.ST, Jefferson, ID

Built 1968 Load: 20.9 t ADT: 180

S. SNAKE RIVER RD

Good

Over: LYONS CREEK

10.0 S. 2.3 E. REXBURG, Madison, ID

Built 1972 Load: 20.9 t ADT: 80

ROAD TO CAMPGROUND

Good

Over: EAST FORK WEISER RIVER

NO DATA ENTERED, Adams, ID

Built 2005 Load: 21.4 t ADT: 50

ROAD

Good

Over: MCCOY CREEK BRIDGE

NO DATA ENTERED, Bonneville, ID

Built 1978 Load: 21.4 t ADT: 50

STC5745;E.FERNAN L

Good

Over: FERNAN LAKE

3 E. 0.3 N. CDA, Kootenai, ID

Built 2010 Load: 21.7 t ADT: 840

STC 4771;SOUTHWICK

Good

Over: POTLATCH RIVER

0.7 N. 0.6 E. KENDRICK, Latah, ID

Built 1995 Load: 21.8 t ADT: 670

STC6731;W 145 N

Good

Over: BURGESS CANAL

9.3 N. 0.9 W. IDAHO FALLS, Jefferson, ID

Built 1961 Load: 21.8 t ADT: 2,600

STC1727;PHILBIN

Good

Over: TYHEE LATERAL CANAL

1.8 N. 1.5 W.CHUBBUCK, Bannock, ID

Built 1949 Load: 21.8 t ADT: 1,300

SAND ROAD

Good

Over: SAND HOLLOW CR

1.6 S. 1.7 E. PARMA, Canyon, ID

Built 1963 Load: 21.8 t ADT: 100

FS ROUTE 489

Good

Over: LIGHTNING CREEK

13 MI FROM CLARK FORK ID, Bonner, ID

Built 1954 Load: 22.4 t ADT: 50

STC2814;LTL WOOD

Good

Over: EAST CANAL

2.5 N. 1.5 W. CAREY, Blaine, ID

Built 1956 Load: 22.7 t ADT: 240

S 2750 E

Good

Over: HEGLAR DRAIN

1.0 W 6.0 S RAFT RIVER, Cassia, ID

Built 1990 Load: 22.7 t ADT: 50

300 WEST ROAD

Good

Over: B-4 CANAL

1.1 S. 3.0 E. PAUL, Minidoka, ID

Built 1968 Load: 22.7 t ADT: 100

SHAW LANE

Good

Over: M.FK.WEISER RIVER

5.0 S. COUNCIL, Adams, ID

Built 1951 Load: 22.7 t ADT: 10

ELK CREEK ROAD

Good

Over: ELK CREEK

14.2 S. RIGGINS, Idaho, ID

Built 1965 Load: 22.7 t ADT: 50

FDR

Good

Over: SLATE CREEK

1 MILE ABOVE SALMON R BR, Custer, ID

Built 1976 Load: 23.0 t ADT: 50

N 1400 E RD (ORME)

Good

Over: OWSLEY CANAL;SE TERRETON

0.9 S. 1.0 E. TERRETON, Jefferson, ID

Built 1976 Load: 23.4 t ADT: 50

SH 39

Good

Over: ABERDEEN SPRINGFIELD CNL

12.0 N. ABERDEEN, Bingham, ID

Built 1977 Load: 23.6 t ADT: 970

STC 4706;WARREN RD

Good

Over: SUMMIT CREEK

3.6 S. 0.8 E. BURGDORF, Idaho, ID

Built 1975 Load: 23.6 t ADT: 110

STC 4706;WARREN RD

Good

Over: LAKE CREEK

1.4 S. 0.7 E. BURGDORF, Idaho, ID

Built 1975 Load: 23.6 t ADT: 110

JACKSON CREEK ROAD

Good

Over: JOHNSON CREEK

1.5 S. 5.2 W. COUNCIL, Adams, ID

Built 2001 Load: 23.6 t ADT: 50

FS ROUTE NO. 301

Good

Over: MERRY CREEK

1.1 MILE FROM CLARKIA ID, Shoshone, ID

Built 1954 Load: 23.7 t ADT: 40

FOREST ROAD 1875

Good

Over: RAINY DAY CREEK

NO DATA ENTERED, Idaho, ID

Built 1972 Load: 23.7 t ADT: 40

FDR

Good

Over: EAST FORK WOOD RIVER

8 MILES SE OF KETCHUM, Blaine, ID

Built 1974 Load: 23.7 t ADT: 50

FS ROUTE 280

Good

Over: GROUSE CREEK

8 MILES NW OF COLBURN ID, Bonner, ID

Built 1987 Load: 24.0 t ADT: 40

FS ROUTE NO. 2636

Good

Over: TRAPPER CREEK

TRAPPER CREEK, Bonner, ID

Built 1973 Load: 24.0 t ADT: 50

N 2900 E(HACKWART)

Good

Over: BUTTE MARKET LAKE CANAL

4.0 S. 0.2 E. ROBERTS, Jefferson, ID

Built 1975 Load: 24.3 t ADT: 30

NO DATA ENTERED

Good

Over: SNAKE CR

NO DATA ENTERED, Idaho, ID

Built 1949 Load: 24.3 t ADT: 40

FS ROUTE NO. 448

Good

Over: ROUND PRAIRIE CREEK

ROUND PRAIRIE CREEK, Boundary, ID

Built 1978 Load: 24.3 t ADT: 40

FDR 381

Good

Over: PALOUSE RIVER

13 MILES FROM POTLATCH ID, Latah, ID

Built 1979 Load: 24.3 t ADT: 15

HUNTER CK-CRKD. R.

Good

Over: CROOKED RIVER

6.8 MI NNW OF DEER PARK, Boise, ID

Built 1963 Load: 24.3 t ADT: 12

NO DATA ENTERED

Good

Over: GOOSE CREEK

NO DATA ENTERED, Adams, ID

Built 1963 Load: 24.3 t ADT: 50

IRR BIA RTE 60

Good

Over: SPRING CREEK

7KM W.JCT HWY 191 & RT 60, Bingham, ID

Built 1975 Load: 24.5 t ADT: 150

Showing 3,101-3,150 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.