State profile · Below median Poor share

Idaho bridge safety

Condition ratings, load ratings, and Poor-condition data for every public highway bridge in Idaho, based on the FHWA National Bridge Inventory.

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

Data updated May 2026

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 whose lowest applicable component is rated 0-4

-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 - Poor-condition share 18.4%
National avg

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

Condition Distribution

Idaho35.4%58.7%GoodFairPoor
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 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.

KS

Kansas

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

WY

Wyoming

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

ID

Idaho

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

MS

Mississippi

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

SC

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 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

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

Poor

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

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

Poor

Over: M.FK.WEISER RIVER

7.3 W 3.4 S DONNELLY, Adams, ID

Built 1957 Load: 4.5 t ADT: 70

2350 NORTH

Poor

Over: CAMAS CREEK

2.5 N. 2.9 W. HAMER, Jefferson, ID

Built 1972 Load: 4.5 t ADT: 20

S ANDERSON LAKE RD

Poor

Over: CD'A RIVER;SPRINGSTON BR

1.7 N. 2.4 E. HARRISON, Kootenai, ID

Built 1955 Load: 6.3 t ADT: 40

LTL WOOD RES. ROAD

Poor

Over: MULDOON CREEK

12.8 N. 2.8 W. CAREY, Blaine, ID

Built 1954 Load: 6.4 t ADT: 30

OLD MIL. RR GRADE

Poor

Over: TROUT CREEK

0.9N 3.1W CALDER, Shoshone, ID

Built 1912 Load: 6.4 t ADT: 15

850 WEST ROAD

Poor

Over: MILNER GOODING CANAL

6.5 N. 8.4 W. SHOSHONE, Lincoln, ID

Built 1950 Load: 7.3 t ADT: 20

AVELENE CK. ROAD

Poor

Over: GRIMES CREEK

9 MI SW OF IDAHO CITY, Boise, ID

Built 1954 Load: 9.1 t ADT: 20

S 100 E

Poor

Over: CLOVER CREEK

6.0 W 5.0 N BLISS, Gooding, ID

Built 1985 Load: 9.1 t ADT: 30

FIFTH STREET

Poor

Over: S.FK.COEUR D'ALENE RIVER

IN MULLAN;FIFTH STREET, Shoshone, ID

Built 1972 Load: 9.1 t ADT: 50

SAGE ROAD

Poor

Over: SUCCOR CREEK

1.0 S. 3.8 W. HOMEDALE, Owyhee, ID

Built 1930 Load: 10.0 t ADT: 90

3214: RUIZ LAKE

Poor

Over: Dietrich Main Canal

3.2 mi E of ID93, Lincoln, ID

Built 1987 Load: 10.4 t ADT: 25

ROSE GARDEN RD

Poor

Over: NOTUS CANAL

CALDWELL;ROSE GARDEN RD, Canyon, ID

Built 1935 Load: 10.9 t ADT: 600

990 SOUTH ROAD

Poor

Over: 'C' CANAL

1.3 S. 2.5 E. HAZELTON, Jerome, ID

Built 1962 Load: 10.9 t ADT: 160

S 1000 W

Poor

Over: TRAIL CREEK

0.1 N. 0.5 W. VICTOR, Teton, ID

Built 1995 Load: 10.9 t ADT: 60

2050 EAST ROAD

Poor

Over: LITTLE WOOD RIVER

0.1 S. 1.5 E. GOODING, Gooding, ID

Built 1930 Load: 11.8 t ADT: 20

OLD HORNET ROAD

Poor

Over: HORNET CREEK

3.5 N. 3.5 W. COUNCIL, Adams, ID

Built 1949 Load: 13.6 t ADT: 100

JIM BROWN BRIDGE R

Poor

Over: LITTLE WOOD RIVER

3.2 N. 3.7 E. RICHFIELD, Lincoln, ID

Built 1965 Load: 13.6 t ADT: 5

FS ROUTE NO. 537

Poor

Over: BIG CREEK

BIG CREEK, Shoshone, ID

Built 1939 Load: 13.6 t ADT: 50

FOREST ROAD 2038

Poor

Over: SLATE CREEK

NO DATA ENTERED, Idaho, ID

Built 1953 Load: 14.3 t ADT: 50

DIVERSION ROAD

Poor

Over: CAMAS CREEK

10.7 S. 1.2 W. KILGORE, Clark, ID

Built 1953 Load: 14.5 t ADT: 50

OLD MIL. RR GRADE

Poor

Over: SLOUGH BRIDGE

1.4N 3.1W CALDER, Shoshone, ID

Built 1912 Load: 14.5 t ADT: 15

FOREST ROAD 357

Poor

Over: RUNNING CR

NO DATA ENTERED, Idaho, ID

Built 1956 Load: 14.6 t ADT: 50

FOREST ROAD 421

Poor

Over: LITTLE MALLARD CREEK

AT SALMON RIVER, Idaho, ID

Built 1984 Load: 14.6 t ADT: 50

FS ROUTE N0. 413

Poor

Over: N.F. CDA RIVER

BREAKWATER, Kootenai, ID

Built 1950 Load: 14.6 t ADT: 50

2421: ASTORQUIA RO

Poor

Over: Twin Falls N. Side Canal

5.0 mi E of ID46, Gooding, ID

Built 1964 Load: 14.9 t ADT: 25

STC 6760;RED ROAD

Poor

Over: CAMAS CREEK

8.1 S. 0.4 W. KILGORE, Clark, ID

Built 1953 Load: 15.4 t ADT: 360

NORTH BIRCH STREET

Poor

Over: LITTLE WOOD RIVER

IN SHOSHONE;N.BIRCH ST, Lincoln, ID

Built 1913 Load: 15.4 t ADT: 200

N 4400 E (SHELTON)

Poor

Over: BURGESS CANAL

4.7 E. 0.6 S. RIGBY, Jefferson, ID

Built 1969 Load: 16.3 t ADT: 510

N. ST. CHARLES

Poor

Over: LEMHI RIVER

0.4 N. 0.3 E. SALMON, Lemhi, ID

Built 1948 Load: 16.3 t ADT: 310

NO DATA ENTERED

Poor

Over: PANTHER CREEK

NO DATA ENTERED, Lemhi, ID

Built 1980 Load: 17.2 t ADT: 200

FS ROUTE NO. 409

Poor

Over: W.F. STEAMBOAT CREEK

W FK STEAMBOAT CR, Shoshone, ID

Built 1956 Load: 17.2 t ADT: 50

SHEEP CAMP RD

Poor

Over: GRANDVIEW IRRIGATION CNL

1.3 E. GRANDVIEW, Owyhee, ID

Built 1991 Load: 18.1 t ADT: 60

FDR

Poor

Over: SOUTH FORK BOISE RIVER

SKUNK CREEK-SO FK JUNCT., Camas, ID

Built 1989 Load: 19.1 t ADT: 12

CUSTER MOTORWAY

Poor

Over: YANKEE FORK

NO DATA ENTERED, Custer, ID

Built 1992 Load: 19.1 t ADT: 100

NO DATA ENTERED

Poor

Over: NO DATA ENTERED

NO DATA ENTERED, Custer, ID

Built 1972 Load: 19.1 t ADT: 50

ROARING RIVER ROAD

Poor

Over: MIDDLE FORK BOISE RIVER

4.5 MI WSW DUTCH CR CABIN, Elmore, ID

Built 1957 Load: 19.8 t ADT: 20

STC2768;2400 E. RD

Poor

Over: MILNER GOODING CANAL

2.5 S. 4.5 E. HAZELTON, Jerome, ID

Built 1970 Load: 19.8 t ADT: 310

COTTONWD-BANNOCK

Poor

Over: MORES CREEK

1 MI ESE OF IDAHO CITY, Boise, ID

Built 1962 Load: 20.7 t ADT: 30

FS ROUTE NO. 456A

Poor

Over: N.F. ST JOE RIVER

LOOP CREEK, Shoshone, ID

Built 1935 Load: 20.7 t ADT: 50

FOREST ROAD 651

Poor

Over: SELWAY RIVER-OHARA

7 MI. FROM LOWELL, ID, Idaho, ID

Built 1956 Load: 21.7 t ADT: 50

1300 N

Poor

Over: HENRYS FK.SNAKE R;FRITZ

1.1 S. 4.0 W. ASHTON, Fremont, ID

Built 1967 Load: 21.8 t ADT: 50

SH 55

Poor

Over: UPRR;N.FK.PAYETTE RIVER

3.0 N. SMITHS FERRY, Valley, ID

Built 1933 Load: 21.8 t ADT: 4,200

EAST FORK ROAD

Poor

Over: S.FK.SALMON RIVER

14.5 W. YELLOW PINE, Valley, ID

Built 1940 Load: 21.8 t ADT: 40

BEAVER-LOON ROAD

Poor

Over: JORDAN CREEK

NO DATA ENTERED, Custer, ID

Built 1957 Load: 23.0 t ADT: 100

STC 5804;WESTSIDE

Poor

Over: MYRTLE CREEK

0.8N. 4.8W. BONNERS FERRY, Boundary, ID

Built 1958 Load: 23.6 t ADT: 300

BURNT LOG ROAD

Poor

Over: JOHNSON CREEK

.5 MI NW LANDMARK AIRSTRP, Valley, ID

Built 1977 Load: 23.7 t ADT: 30

BOULDER CREEK ROAD

Poor

Over: MORES CREEK

5 MI NE IDAHO CITY, Boise, ID

Built 1982 Load: 24.0 t ADT: 50

Showing 1,651-1,700 of 1,742 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.

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