State profile · Below national median SD

Idaho bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in Idaho — drawn straight from the FHWA National Bridge Inventory.

1,742
Public bridges
33.3%
Good condition
5.5%
Poor condition
5.5%
Structurally deficient

Total Bridges

1,742

Public highway bridges in Idaho

Good Condition

33.3%

580 bridges rated 7-9

-16.7pp vs 50% benchmark

Poor Condition

5.5%

96 bridges rated 0-4

Structurally Deficient

5.5%

96 bridges flagged for repair priority

-1.5pp vs national avg 7.0%

Idaho vs national bridge condition

Idaho — Good condition share 33.3%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Idaho — Structurally deficient share 18.4%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Bridge inventory deck-condition mix — Idaho (FHWA NBI)

Idaho33.295063145809415%55.166475315729045%GoodFairPoorStructurally Deficient
Bridge inventory deck-condition mix — Idaho (FHWA NBI)

Counties (44)

Ada 81 Adams 42 Bannock 25 Bear Lake 13 Benewah 15 Bingham 75 Blaine 39 Boise 41 Bonner 47 Bonneville 50 Boundary 52 Butte 14 Camas 26 Canyon 77 Caribou 12 Cassia 38 Clark 18 Clearwater 65 Custer 81 Elmore 45 Franklin 4 Fremont 46 Gem 16 Gooding 25 Idaho 130 Jefferson 55 Jerome 26 Kootenai 60 Latah 26 Lemhi 73 Lewis 6 Lincoln 16 Madison 27 Minidoka 19 Nez Perce 19 Oneida 2 Owyhee 20 Payette 9 Power 13 Shoshone 139 Teton 13 Twin Falls 35 Valley 82 Washington 25

Idaho vs nearby ranks

Adjacent states on the structurally deficient leaderboard (lower share = better)

States are ranked by share of bridges flagged structurally deficient — the FHWA classification for any span where deck, superstructure, or substructure carries a condition rating of 4 or below. Lower percentages indicate stronger maintenance funding and inspection follow-through. States here sit immediately above and below Idaho on the same metric.

20

Kansas

5.25% top marginal rate
Structure
Progressive
Burden @ $100K
$23,867

56

Wyoming

5.41% top marginal rate
Structure
Progressive
Burden @ $100K
$3,181
Selected

16

Idaho

5.51% top marginal rate
Structure
Progressive
Burden @ $100K
$1,742

28

Mississippi

5.92% top marginal rate
Structure
Progressive
Burden @ $100K
$16,823

45

South Carolina

6.10% top marginal rate
Structure
Progressive
Burden @ $100K
$5,396

Bridges Needing Most Attention in Idaho

Six lowest-condition bridges in Idaho, ranked by composite NBI rating. Each is inspected at least every 24 months.

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

SWAMP ROAD

Poor

Over: CAMAS CREEK

1.5 S. 0.3 E. HILL CITY, Camas, ID

Built 1965 Load: 1.8 t ADT: 40

ROAD 50343

Poor

Over: LOGAN CREEK

NO DATA ENTERED, Valley, ID

Built 1980 Load: 2.6 t ADT: 50

VADNAIS LANE

Poor

Over: CAMAS CREEK

1.9 S. 0.6 E. KILGORE, Clark, ID

Built 1981 Load: 2.7 t ADT: 50

2701: NORTH MILNER

Poor

Over: Milner Gooding Canal

5.0 mi N of Hunt Rd, Jerome, ID

Built 1960 Load: 4.2 t ADT: 25

MIDDLE FORK ROAD

Structurally Deficient

Over: M.FK.WEISER RIVER

7.3 W 3.4 S DONNELLY, Adams, ID

Built 1957 Load: 4.5 t ADT: 70

All Bridges in Idaho

HATTER CREEK ROAD

Fair

Over: HATTER CREEK

2.6 S. 0.4 E. PRINCETON, Latah, ID

Built 1965 Load: 12.7 t ADT: 30

STC 6774;E 2000 N

Fair

Over: S.FK.TETON RIVER

1.2 S. 1 E. SUGAR CITY, Madison, ID

Built 1959 Load: 12.7 t ADT: 1,600

KING LANE

Fair

Over: WARM SPRING CREEK

2.0 S. 1.4 W. ROCKLAND, Power, ID

Built 1965 Load: 12.7 t ADT: 80

NO DATA ENTERED

Fair

Over: JORDAN CREEK

NO DATA ENTERED, Custer, ID

Built 1972 Load: 13.0 t ADT: 100

NO DATA ENTERED

Fair

Over: JUNGLE CREEK

NO DATA ENTERED, Adams, ID

Built 1982 Load: 13.3 t ADT: 50

LAKE WAY

Fair

Over: NORTH FORK PAYETTE RIVER

DOWNSTREAM OF CASCADE DAM, Valley, ID

Built 1913 Load: 13.3 t ADT: 100

S DAISY STREET

Fair

Over: SPRING CREEK

IN SALMON;DAISY ST, Lemhi, ID

Built 1975 Load: 13.6 t ADT: 250

920 NORTH ROAD

Fair

Over: STRATTON CANAL

1.5 N. 1.0 E. RICHFIELD, Lincoln, ID

Built 1960 Load: 13.6 t ADT: 80

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

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

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

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

STUMP GS ROAD

Fair

Over: STUMP CREEK

NO DATA ENTERED, Caribou, ID

Built 1973 Load: 13.9 t ADT: 10

FOREST ROAD 1614

Fair

Over: SALMON RIVER

6.4 MI. FROM RIGGINS, ID, Idaho, ID

Built 1949 Load: 13.9 t ADT: 140

DANSKIN ROAD

Fair

Over: S. FK. BOISE RIVER

7 MI NW ANDRSN RNCH DAM, Elmore, ID

Built 1957 Load: 14.3 t ADT: 10

FORMELT ROAD

Fair

Over: OROFINO CREEK

IN PEIRCE, Clearwater, ID

Built 2000 Load: 14.5 t ADT: 190

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

MCDONALD ROAD

Fair

Over: SHEBANG CREEK

6.3 N. 5.0 W. GRANGEVILLE, Idaho, ID

Built 1970 Load: 14.5 t ADT: 70

WEST CAMAS ROAD

Fair

Over: CAMAS CREEK

0.7 MI. W OF HDQTRS, Jefferson, ID

Built 1940 Load: 14.5 t ADT: 5

HELLS GATE RD

Fair

Over: TAMMANY CREEK

IN HELL'S GATE STATE PARK, Nez Perce, ID

Built 1959 Load: 14.5 t ADT: 330

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 326

Fair

Over: FRAZIER CREEK

10 MILES FROM AVERY, ID, Shoshone, ID

Built 1938 Load: 14.6 t ADT: 50

NO DATA ENTERED

Fair

Over: YANKEE FORK

NO DATA ENTERED, Custer, ID

Built 1972 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

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

FDR

Fair

Over: WOOD RIVER

13 MILES FROM SNRA HQTS, Blaine, ID

Built 1962 Load: 15.2 t ADT: 50

ERICKSON RD

Fair

Over: BENEWAH CREEK

3.7 N. 3.1 E. BENEWAH, Benewah, ID

Built 1970 Load: 15.4 t ADT: 50

EMERSON ST.

Fair

Over: BUTTE ARM CANAL

IN IDAHO FALLS;EMERSON ST, Bonneville, ID

Built 1956 Load: 15.4 t ADT: 670

TUCKER ROAD

Fair

Over: DIXIE SLOUGH

1.2 N. 3.4 E. WILDER, Canyon, ID

Built 1990 Load: 15.4 t ADT: 20

TERROR GULCH

Fair

Over: S.FK.CD'A R;TERROR GULCH

0.7 N. 1.1 W. OSBURN, Shoshone, ID

Built 1973 Load: 15.4 t ADT: 870

FOREST ROAD 233

Fair

Over: E. FK. CROOKED RIVER

NO DATA ENTERED, Idaho, ID

Built 2004 Load: 15.6 t ADT: 50

SIXBIT ROAD

Fair

Over: S. FK SALMON RIVER

5 MI N. OF WARM LAKE, Valley, ID

Built 1976 Load: 15.6 t ADT: 15

SIX ML.-RD.VALLEY

Fair

Over: MIDDLE FK PAYETTE RIVER

17 MI N. OF CROUCH, ID, Valley, ID

Built 1975 Load: 15.6 t ADT: 20

FDR 581

Fair

Over: KELLY CREEK

OLD KELLY RANGER STATION, Clearwater, ID

Built 1940 Load: 15.9 t ADT: 30

FDR 255

Fair

Over: MOOSE CREEK

MOOSE & KELLY CR JCT, Clearwater, ID

Built 1949 Load: 15.9 t ADT: 40

CAMPGROUND ROAD

Fair

Over: CUB RIVER

NO DATA ENTERED, Franklin, ID

Built 1964 Load: 15.9 t ADT: 30

FDR

Fair

Over: PARIDISE CREEK

BIG SMOKY JCT, Camas, ID

Built 1977 Load: 16.2 t ADT: 50

FS ROUTE NO. 509

Fair

Over: BLUFF CREEK

BLUFF CREEK, Shoshone, ID

Built 1993 Load: 16.2 t ADT: 50

SMA3343;COLUMBIA

Fair

Over: RAWSON CANAL

2.8 N 3.3 E KUNA, Ada, ID

Built 1976 Load: 16.3 t ADT: 3,400

LITTLE INDIAN ROAD

Fair

Over: BLACKFOOT RIVER

3.5 S. 2.3 E. FIRTH, Bingham, ID

Built 1978 Load: 16.3 t ADT: 200

W 400 N;WAREING RD

Fair

Over: PEOPLES CANAL

2.4 N. 0.5 E. GROVELAND, Bingham, ID

Built 1976 Load: 16.3 t ADT: 100

S 2400 W; ANDERSON

Fair

Over: HIGH LINE CANAL

4.5 W. 0.2 N SPRINGFIELD, Bingham, ID

Built 1974 Load: 16.3 t ADT: 100

UNDERWOOD ROAD

Fair

Over: HIGH LINE CANAL

4.5N. 0.5E.ABERDEEN;2700W, Bingham, ID

Built 1970 Load: 16.3 t ADT: 120

SHEEP TRAIL

Fair

Over: ABERDEEN SPRINGFIELD CNL

1.5 N. 0.1 E. PINGREE, Bingham, ID

Built 1966 Load: 16.3 t ADT: 200

FAIRVIEW ROAD

Fair

Over: HIGH LINE CANAL

2.4 S. 1.5 W. ABERDEEN, Bingham, ID

Built 1971 Load: 16.3 t ADT: 200

STC 1844;HOFF ROAD

Fair

Over: ABERDEEN SPRINGFIELD CNL

0.5 N. 0.1 E. ROCKFORD, Bingham, ID

Built 1990 Load: 16.3 t ADT: 700

Showing 151-200 of 1,742 bridges

Related

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Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges Editorial.

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). A "structurally deficient" rating is a repair-priority signal, not a closure or unsafe-to-cross designation. Consult a qualified civil engineer before making decisions based on this data.

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.