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 1879;LONG VLY

Fair

Over: WILLOW CREEK

3.8 S. 22.0 E. FIRTH, Bingham, ID

Built 1999 Load: 20.9 t ADT: 80

STC2713;CROSS CNTY

Fair

Over: DEEP CREEK

4.4 S. 3.8 W. BUHL, Twin Falls, ID

Built 1980 Load: 20.9 t ADT: 1,400

STC2721;2200 E. RD

Fair

Over: LOW LINE CANAL

1.8 S. FILER;3725N-2200E, Twin Falls, ID

Built 1964 Load: 20.9 t ADT: 1,200

STC2729;3400 N. RD

Fair

Over: HIGH LINE CANAL

2.5 E. US 93;3400N-2650E, Twin Falls, ID

Built 1964 Load: 20.9 t ADT: 320

W 200 SOUTH ROAD

Fair

Over: J CANAL

2.3 S. 3.1 W. BURLEY, Cassia, ID

Built 1977 Load: 20.9 t ADT: 340

STC2839;500 SOUTH

Fair

Over: J CANAL

4.1S 1.4W DECLO;730E-500S, Cassia, ID

Built 1975 Load: 20.9 t ADT: 1,700

F STREET

Fair

Over: MAIN NORTHSIDE CANAL

AT ACEQUIA SCL;325N-365E, Minidoka, ID

Built 1960 Load: 20.9 t ADT: 250

STC 3734;LAKE AVE

Fair

Over: PHYLLIS CANAL

3.3 N. 8.0 E. MARSING, Canyon, ID

Built 1995 Load: 20.9 t ADT: 4,700

STC 3740;NOTUS RD

Fair

Over: RIVERSIDE CANAL

3.0 S. NOTUS, Canyon, ID

Built 1940 Load: 20.9 t ADT: 1,700

SMA 8523;CHERRY LN

Fair

Over: PHYLLIS CANAL

2.8 N. 2.6 E. NAMPA, Canyon, ID

Built 1976 Load: 20.9 t ADT: 6,800

STC 3770;STAR RD

Fair

Over: FIVE MILE FEEDER

3.28 S. STAR, Ada, ID

Built 1966 Load: 20.9 t ADT: 10,500

STC 3810;GRAVEL RD

Fair

Over: I 84;PASADENA VALLEY IC

4.8 E. GLENNS FERRY, Elmore, ID

Built 1975 Load: 20.9 t ADT: 240

LICK CREEK ROAD

Fair

Over: SECESH RIVER

20.2 E. MCCALL, Valley, ID

Built 1952 Load: 20.9 t ADT: 40

STC5750;PINE CREEK

Fair

Over: PINE CREEK

3.4 S. PINEHURST, Shoshone, ID

Built 1956 Load: 20.9 t ADT: 620

STC5758;BEAVER CRK

Fair

Over: COEUR DALENE RIVER

2.0 S. PRICHARD, Shoshone, ID

Built 1979 Load: 20.9 t ADT: 130

STC 5803;MOYIE RVR

Fair

Over: MOYIE RIVER;SINCLAIR BR.

1.2 S. ADDIE, Boundary, ID

Built 1975 Load: 20.9 t ADT: 120

STC 5805;WESTSIDE

Fair

Over: SMITH CREEK

2.6 S. 2.7 W. PORTHILL, Boundary, ID

Built 1970 Load: 20.9 t ADT: 70

STC 6703;E 65TH S

Fair

Over: IDAHO CANAL

3.6 S. 1.2 E. IDAHO FALLS, Bonneville, ID

Built 1950 Load: 20.9 t ADT: 3,800

STC 6705; S 15TH E

Fair

Over: SAND CREEK

4.8 S. 1.9 E. IDAHO FALLS, Bonneville, ID

Built 1952 Load: 20.9 t ADT: 1,900

STC6731;CO LINE RD

Fair

Over: HARRISON CANAL

2.3 N. 5.8 E. UCON, Bonneville, ID

Built 1974 Load: 20.9 t ADT: 1,800

STC 6748(N 3950 E)

Fair

Over: DRY BED

2.1 N. RIGBY, Jefferson, ID

Built 1968 Load: 20.9 t ADT: 700

STC 6748(N 3950 E)

Fair

Over: LONG ISLAND CANAL

3.4 N. RIGBY, Jefferson, ID

Built 1975 Load: 20.9 t ADT: 700

STC 6768; S2000W

Fair

Over: REID CANAL

1.3 E. 2.7 S. THORNTON, Madison, ID

Built 1960 Load: 20.9 t ADT: 2,000

STC 6851; S 1ST E

Fair

Over: SAND CREEK

2.5 N. TAYLOR, Bonneville, ID

Built 1962 Load: 20.9 t ADT: 1,300

PALOMINO DRIVE

Fair

Over: SAND CREEK

2.6 N. 0.1 E. TAYLORVILLE, Bonneville, ID

Built 2003 Load: 20.9 t ADT: 50

SMA 7113;CURTIS RD

Fair

Over: RIDENBAUGH CANAL

IN BOISE;CURTIS RD., Ada, ID

Built 1961 Load: 20.9 t ADT: 13,000

SMA 7166;1ST ST

Fair

Over: SAND CREEK

AMMON, Bonneville, ID

Built 1957 Load: 20.9 t ADT: 14,000

STC 7233;ROOSEVELT

Fair

Over: NEW YORK CANAL

IN BOISE;ROOSEVELT ST., Ada, ID

Built 1975 Load: 20.9 t ADT: 1,400

SMA7316;HOLMES AVE

Fair

Over: IDAHO CANAL

IN IDAHO FALLS, Bonneville, ID

Built 1999 Load: 20.9 t ADT: 12,500

SMA 7403;FRANKLIN

Fair

Over: RIDENBAUGH CANAL

0.1 E. LIBERTY/FRANKLIN, Ada, ID

Built 1984 Load: 20.9 t ADT: 11,500

NHS 7433;VISTA AVE

Fair

Over: RIDENBAUGH CANAL

IN BOISE;VISTA AVE., Ada, ID

Built 1947 Load: 20.9 t ADT: 19,000

STC 7631;SHILLING

Fair

Over: BLACKFOOT RIVER

AT BLACKFOOT SCL, Bingham, ID

Built 1971 Load: 20.9 t ADT: 1,700

STC 7664;W. 6TH ST

Fair

Over: PARADISE CREEK

IN MOSCOW;W.6TH ST., Latah, ID

Built 1916 Load: 20.9 t ADT: 7,300

STP7713;FARMWAY RD

Fair

Over: PHYLLIS CANAL

1.9 S. 1.3 W. CALDWELL, Canyon, ID

Built 1967 Load: 20.9 t ADT: 5,900

STC7853;N.ILLINOIS

Fair

Over: NOTUS CANAL

IN CALDWELL;N.ILLINOIS AV, Canyon, ID

Built 1977 Load: 20.9 t ADT: 4,500

SMA8323;SOUTH SIDE

Fair

Over: NEW YORK CANAL

3.5S. 1.5E. NAMPA CTY CTR, Canyon, ID

Built 1977 Load: 20.9 t ADT: 2,300

STC 8423;LK LOWELL

Fair

Over: DEER FLAT NAMPA CANAL

1.3 S 2.8 W NAMPA, Canyon, ID

Built 1992 Load: 20.9 t ADT: 6,200

SMA 7563;OVERLAND

Fair

Over: TEN MILE CREEK

1.0 S. 0.1 E. MERIDIAN, Ada, ID

Built 1986 Load: 20.9 t ADT: 24,000

STC8783;CENTER AVE

Fair

Over: LOWER PAYETTE DITCH

IN PAYETTE;CENTER AVE, Payette, ID

Built 1967 Load: 20.9 t ADT: 1,400

STC 1764; PARK ST.

Fair

Over: PORTNEUF RIVER

AT INKOM SCL, Bannock, ID

Built 1940 Load: 20.9 t ADT: 1,100

W. LINCOLN AVE

Fair

Over: RAPID CREEK

W. LINCOLN AVE IN INKOM, Bannock, ID

Built 1997 Load: 20.9 t ADT: 100

STC1842;RISING RVR

Fair

Over: ABERDEEN SPRINGFIELD CNL

5.0 N. 1.0 E. BLACKFOOT, Bingham, ID

Built 1993 Load: 20.9 t ADT: 550

STC1842;RISING RVR

Fair

Over: LAVASIDE CANAL

5.2 N. 1.0 E. BLACKFOOT, Bingham, ID

Built 1993 Load: 20.9 t ADT: 550

BOND ROAD

Fair

Over: PEOPLES CANAL

2.3 N. 1.2 W. GROVELAND, Bingham, ID

Built 1978 Load: 20.9 t ADT: 100

AIRPORT ROAD

Fair

Over: HIGH LINE CANAL

1.5 S. 1.7 W. ABERDEEN, Bingham, ID

Built 1963 Load: 20.9 t ADT: 200

CLINGER RD; 1450 N

Fair

Over: SNAKE RIVER VALLEY CANAL

1.5 N. 1.0 E. SHELLEY, Bingham, ID

Built 1960 Load: 20.9 t ADT: 260

HUNSNGR LP;W.2050S

Fair

Over: HIGH LINE CANAL

3.0 S. 1.8 W.ABERDEEN, Bingham, ID

Built 1977 Load: 20.9 t ADT: 95

CHRISTENSEN; 150 E

Fair

Over: ABERDEEN SPRINGFIELD CNL

6.2 N. 3.5 E. BLACKFOOT, Bingham, ID

Built 1973 Load: 20.9 t ADT: 140

STC 1840;WOLVERINE

Fair

Over: BLACKFOOT CANAL

1.5 S. 0.9 W. FIRTH, Bingham, ID

Built 1964 Load: 20.9 t ADT: 520

PRESTO ROAD

Fair

Over: SAND CREEK

0.2 S. 2.3 E. KIMBALL, Bingham, ID

Built 1930 Load: 20.9 t ADT: 140

Showing 501-550 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.