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

LONG GULCH ROAD

Fair

Over: M.FK.BOISE RIVER

10.0 N. 8.5 W. PRAIRIE, Boise, ID

Built 1954 Load: 12.7 t ADT: 120

FH 212;BUCKHORN CR

Fair

Over: S.FK.CLEARWATER RIVER

1.5 E. GOLDEN, Idaho, ID

Built 1950 Load: 12.7 t ADT: 50

COUNTY ROAD

Fair

Over: N.FK.SKOOKUMCHUCK CREEK

3.0 S. 4.0 E. WHITEBIRD, Idaho, ID

Built 1965 Load: 12.7 t ADT: 50

S. BRINCKEN ROAD

Fair

Over: DEEP CREEK

5.4 N. 1.1 W. POTLATCH, Latah, ID

Built 1940 Load: 12.7 t ADT: 10

HATTER CREEK ROAD

Fair

Over: HATTER CREEK

2.6 S. 0.4 E. PRINCETON, Latah, ID

Built 1965 Load: 12.7 t ADT: 30

RIVER ROAD

Fair

Over: PINE CREEK

1.7 N. 3.6 E. MYRTLE, Nez Perce, ID

Built 1929 Load: 12.7 t ADT: 30

LANDMARK/STANLEY

Fair

Over: BEAR VALLEY CREEK

7N 14E DEADWOOD RES, Valley, ID

Built 1961 Load: 12.7 t ADT: 30

NO DATA ENTERED

Fair

Over: JORDAN CREEK

NO DATA ENTERED, Custer, ID

Built 1972 Load: 13.0 t ADT: 100

LAKE WAY

Fair

Over: NORTH FORK PAYETTE RIVER

DOWNSTREAM OF CASCADE DAM, Valley, ID

Built 1913 Load: 13.3 t ADT: 100

NO DATA ENTERED

Fair

Over: JUNGLE CREEK

NO DATA ENTERED, Adams, ID

Built 1982 Load: 13.3 t ADT: 50

STC 4747;CNTRL RDG

Fair

Over: BIG CANYON CREEK

0.3 S. PECK, Nez Perce, ID

Built 1948 Load: 13.6 t ADT: 30

MISSION CREEK ROAD

Fair

Over: MISSION CREEK

3.1 S. JACQUES SPUR, Nez Perce, ID

Built 1947 Load: 13.6 t ADT: 170

STC 5711;MOON PASS

Fair

Over: BULLION CREEK

8.7 N. 1.9 E. AVERY, Shoshone, ID

Built 1937 Load: 13.6 t ADT: 210

STC 6707; E 97TH S

Fair

Over: SAND CREEK

2.0 N. 0.75 E.TAYLORVILLE, Bonneville, ID

Built 1969 Load: 13.6 t ADT: 900

1400 SOUTH ROAD

Fair

Over: CANAL

4.0 N. 1.7 E. GOODING, Gooding, ID

Built 1930 Load: 13.6 t ADT: 50

920 NORTH ROAD

Fair

Over: STRATTON CANAL

1.5 N. 1.0 E. RICHFIELD, Lincoln, ID

Built 1960 Load: 13.6 t ADT: 80

S5765;SILVR VALLEY

Fair

Over: MOON GULCH

0.1 S. 3.0 E. KELLOGG, Shoshone, ID

Built 1950 Load: 13.6 t ADT: 1,400

POTLATCH ROAD

Fair

Over: BIG CREEK TRESTLE

4.1 E. CALDER, Shoshone, ID

Built 1912 Load: 13.6 t ADT: 100

S DAISY STREET

Fair

Over: SPRING CREEK

IN SALMON;DAISY ST, Lemhi, ID

Built 1975 Load: 13.6 t ADT: 250

STC 6785;DIGGER DR

Fair

Over: TETON ISLAND CANAL

0.4 S. 0.5 E. SUGAR CITY, Madison, ID

Built 1959 Load: 13.6 t ADT: 700

BIG CREEK ROAD

Fair

Over: PROFILE CREEK

2.9 N 4.3 E YELLOW PINE, Valley, ID

Built 2010 Load: 13.6 t ADT: 10

FS ROUTE NO. 419

Fair

Over: LIGHTNING CREEK

LIGHTNING CREEK, Bonner, ID

Built 1959 Load: 13.9 t ADT: 50

FS ROUTE NO. 231

Fair

Over: ZUNI CREEK

ZUNI CREEK, Boundary, ID

Built 1987 Load: 13.9 t ADT: 50

FOREST ROAD 1614

Fair

Over: SALMON RIVER

6.4 MI. FROM RIGGINS ID, Idaho, ID

Built 1949 Load: 13.9 t ADT: 140

STUMP GS ROAD

Fair

Over: STUMP CREEK

NO DATA ENTERED, Caribou, ID

Built 1973 Load: 13.9 t ADT: 10

DANSKIN ROAD

Fair

Over: S. FK. BOISE RIVER

7 MI NW ANDRSN RNCH DAM, Elmore, ID

Built 1957 Load: 14.3 t ADT: 10

SH 14

Fair

Over: MEADOW CREEK

14.1 W. GOLDEN, Idaho, ID

Built 1983 Load: 14.5 t ADT: 150

STC 3730;RIVERSIDE

Fair

Over: MORA CANAL

1.4 N. 3.1 E. MARSING, Canyon, ID

Built 1967 Load: 14.5 t ADT: 970

STC 3879;BURTON LN

Fair

Over: CREEK;SLOUGH

1.5 S. 1.0 E. CAMBRIDGE, Washington, ID

Built 1935 Load: 14.5 t ADT: 190

STC 5756;BIG CR RD

Fair

Over: BIG CREEK;SUNSHINE MINE

6.1 E. KELLOGG, Shoshone, ID

Built 1974 Load: 14.5 t ADT: 350

WILLOW BEND; 1400W

Fair

Over: ABERDEEN SPRINGFIELD CNL

1.0 S. 1.0 W. LIBERTY, Bingham, ID

Built 1962 Load: 14.5 t ADT: 240

BURTON ROAD

Fair

Over: LAST CHANCE CANAL

2.2 N. 1.2 E. GRACE, Caribou, ID

Built 1983 Load: 14.5 t ADT: 25

1625 EAST ROAD

Fair

Over: BIG WOOD RIVER

1.7 N. 2.7 W. GOODING, Gooding, ID

Built 1999 Load: 14.5 t ADT: 30

370 SOUTH ROAD

Fair

Over: MILNER GOODING CANAL

2.0 S. 0.3 E. DIETRICH, Lincoln, ID

Built 1944 Load: 14.5 t ADT: 100

CEMETARY LANE

Fair

Over: HORNET CREEK

5.1 N 5.3 W. COUNCIL, Adams, ID

Built 1950 Load: 14.5 t ADT: 100

STC3841;WEITZ RD

Fair

Over: WEST END DRAIN

0.2 N. 3.8 W. CALDWELL, Canyon, ID

Built 1962 Load: 14.5 t ADT: 640

MCCOY BRIDGE RD

Fair

Over: S.FK.BOISE RIVER;NE.PINE

1.1 N. 0.1 E. PINE, Elmore, ID

Built 1954 Load: 14.5 t ADT: 70

CRANE CRK RES RD

Fair

Over: CRANE CREEK

7.8 S. 5.9 E. MIDVALE, Washington, ID

Built 1970 Load: 14.5 t ADT: 5

FORMELT ROAD

Fair

Over: OROFINO CREEK

IN PEIRCE, Clearwater, ID

Built 2000 Load: 14.5 t ADT: 190

MCDONALD ROAD

Fair

Over: SHEBANG CREEK

6.3 N. 5.0 W. GRANGEVILLE, Idaho, ID

Built 1970 Load: 14.5 t ADT: 70

LEON ROAD

Fair

Over: UNION FLAT CREEK

1.5 S. 5.3 W. GENESEE, Nez Perce, ID

Built 1938 Load: 14.5 t ADT: 40

HELLS GATE RD

Fair

Over: TAMMANY CREEK

IN HELLS GATE STATE PARK, Nez Perce, ID

Built 1959 Load: 14.5 t ADT: 330

DIVERSION ROAD

Fair

Over: DRY GULCH

10.8 S. 1.2 W KILGORE, Clark, ID

Built 2007 Load: 14.5 t ADT: 5

WEST CAMAS ROAD

Fair

Over: CAMAS CREEK

0.7 MI. W OF HDQTRS, Jefferson, ID

Built 1940 Load: 14.5 t ADT: 5

FS ROUTE 326

Fair

Over: FRAZIER CREEK

10 MILES FROM AVERY ID, Shoshone, ID

Built 1938 Load: 14.6 t ADT: 50

FOREST ROAD 1875

Fair

Over: S.FK.CLWTR RIVER

20 MI. FROM ELK CITY ID, Idaho, ID

Built 1973 Load: 14.6 t ADT: 50

FS ROUTE NO. 301

Fair

Over: FISHHOOK CREEK

FISHHOOK CREEK, Shoshone, ID

Built 1938 Load: 14.9 t ADT: 50

FS ROUTE 303

Fair

Over: ST JOE RIVER

2 MI F/ RED IVES W. C., Shoshone, ID

Built 1935 Load: 14.9 t ADT: 50

FS ROUTE 225

Fair

Over: ST JOE RIVER

AT STANLEY RANCH, Shoshone, ID

Built 1934 Load: 14.9 t ADT: 50

FOREST ROAD 470

Fair

Over: SELWAY R SWIFTWATER

3 MI. FROM LOWELL ID, Idaho, ID

Built 1936 Load: 14.9 t ADT: 50

Showing 101-150 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.