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

M.FK.PAYETTE R. RD

Good

Over: M.FK. PAYETTE RIVER

3 MI N TRAIL CREEK CG, Valley, ID

Built 1957 Load: 13.0 t ADT: 50

NO DATA ENTERED

Good

Over: NO DATA ENTERED

NO DATA ENTERED, Custer, ID

Built 1972 Load: 13.9 t ADT: 100

PRIVATE ROAD

Good

Over: MORES CREEK

6.2 S. 5.2 W. IDAHO CITY, Boise, ID

Built 1985 Load: 14.5 t ADT: 15

BRINDLEY ROAD

Good

Over: CAMAS CREEK

1.9 MI. SSW OF HDQTRS, Jefferson, ID

Built 1980 Load: 14.5 t ADT: 10

FS ROUTE NO. 2116A

Good

Over: BEAVER CREEK

BEAVER CREEK CAMPGROUND, Bonner, ID

Built 1986 Load: 14.6 t ADT: 50

FOREST ROAD 233

Good

Over: WILDHORSE CREEK

NEAR OROGRANDE SUMMIT, Idaho, ID

Built 1955 Load: 15.6 t ADT: 50

N.FK. BOISE R. RD.

Good

Over: MORES CREEK

2 MI EAST OF IDAHO CITY, Boise, ID

Built 1955 Load: 16.2 t ADT: 79

N 1700 E

Good

Over: EGIN CANAL

0.8 N. 1.0 E. EGIN, Fremont, ID

Built 1980 Load: 16.3 t ADT: 20

STC 1718;ARBON VLY

Good

Over: BANNOCK CR.;MICHAUD BR.

15.6 N. PAULINE, Power, ID

Built 1964 Load: 16.3 t ADT: 320

FS ROUTE 301

Good

Over: FISHHOOK CREEK

6 MI FROM AVERY, ID, Shoshone, ID

Built 1975 Load: 16.5 t ADT: 50

FS ROUTE 218

Good

Over: RED IVES CREEK

AT RED IVES WORK CENTER, Shoshone, ID

Built 1936 Load: 16.5 t ADT: 50

FDR

Good

Over: SOUTH FORK BOISE RIVER

10 MILES WEST FEATHERVILE, Elmore, ID

Built 1956 Load: 16.8 t ADT: 50

FS ROUTE 302

Good

Over: GRANITE CREEK

4 MI. FROM NORDMAN, ID, Bonner, ID

Built 1952 Load: 17.2 t ADT: 50

FS ROUTE NO. 2646

Good

Over: N. CARIBOU CR

NORTH CARIBOU CREEK, Boundary, ID

Built 1987 Load: 17.5 t ADT: 50

NO DATA ENTERED

Good

Over: E.F. BIG CREEK

EAST FORK BIG CREEK, Shoshone, ID

Built 1994 Load: 17.5 t ADT: 50

FDR

Good

Over: WOOD RIVER

4MILES WEST SNRA HQTS, Blaine, ID

Built 1959 Load: 17.8 t ADT: 50

ROARING RIVER ROAD

Good

Over: ROARING RIVER

4.5 MI WSW DUTCH CK CABIN, Elmore, ID

Built 1957 Load: 17.8 t ADT: 20

FS ROUTE 1013

Good

Over: GOLD CREEK

18 MI.FROM NORDMAN, ID., Bonner, ID

Built 1965 Load: 18.1 t ADT: 50

STC 6743 (E 200 N)

Good

Over: MARKET LAKE CANAL

4.5 S. 0.7 E. ROBERTS, Jefferson, ID

Built 1959 Load: 18.1 t ADT: 760

MAIERS LANE

Good

Over: LEMHI RIVER

3.7 S. 2.9 E. LEMHI, Lemhi, ID

Built 1977 Load: 18.1 t ADT: 120

ROAD 50260

Good

Over: TRAIL CREEK

MP 0.7 OF 50260, Valley, ID

Built 1991 Load: 18.1 t ADT: 50

FS ROUTE NO. 2443

Good

Over: SMITH CREEK

SMITH CREEK, Boundary, ID

Built 1964 Load: 18.5 t ADT: 50

LONG CREEK ROAD

Good

Over: CLEAR CREEK

4.5 MI NE OF LOWMAN ID, Boise, ID

Built 1980 Load: 18.8 t ADT: 20

1901: HERD CREEK

Good

Over: East Fork Salmon River

9 mi S of ID75, Custer, ID

Built 1964 Load: 18.8 t ADT: 25

NO DATA ENTERED

Good

Over: SKULL CREEK

2.5 MI FROM ROAD 247, Clearwater, ID

Built 1967 Load: 19.1 t ADT: 50

FDR

Good

Over: BIG BOULDER CREEK

20 MILES UP EAST FORK S R, Custer, ID

Built 1980 Load: 19.1 t ADT: 50

NO DATA ENTERED

Good

Over: WHITE CAP CR

NO DATA ENTERED, Idaho, ID

Built 1936 Load: 19.1 t ADT: 20

S 2000 E

Good

Over: DARBY CREEK

3.3 S. 2.5 E. DRIGGS, Teton, ID

Built 2014 Load: 19.1 t ADT: 200

CURTIS CUTOFF ROAD

Good

Over: CURTIS CREEK

2 MI WEST OF WARM LAKE, Valley, ID

Built 1963 Load: 19.1 t ADT: 5

N.FK. BOISE R. RD.

Good

Over: CROOKED RIVER

3 MI N OF BARBER FLAT, Boise, ID

Built 1957 Load: 19.8 t ADT: 40

HUNTER CK-CRKD. R.

Good

Over: BEAR CREEK

3.8 MI N.W. OF DEER PARK, Boise, ID

Built 1963 Load: 19.8 t ADT: 12

NO DATA ENTERED

Good

Over: SELWAY RIVER

NO DATA ENTERED, Idaho, ID

Built 1935 Load: 20.1 t ADT: 10

FDR

Good

Over: LITTLE SMOKY CREEK

18 MILES NORTH FAIRFIELD, Camas, ID

Built 1959 Load: 20.4 t ADT: 50

FDR

Good

Over: FISHHOOK CREEK

REDFISH LAKE, Custer, ID

Built 1975 Load: 20.4 t ADT: 50

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: BIG SMOKY CREEK

BIG SMOKY JCT, Camas, ID

Built 1977 Load: 20.7 t ADT: 50

FS ROUTE NO. 326

Good

Over: LOOP CREEK

LOOP CR, Shoshone, ID

Built 1999 Load: 20.7 t ADT: 40

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

STC 4771;SOUTHWICK

Good

Over: POTLATCH RIVER

0.7 N. 0.6 E. KENDRICK, Latah, ID

Built 1995 Load: 21.8 t ADT: 670

FS ROUTE 489

Good

Over: LIGHTNING CREEK

13 MI FROM CLARK FORK, ID, Bonner, ID

Built 1954 Load: 22.4 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

JACKSON CREEK ROAD

Good

Over: JOHNSON CREEK

1.5 S. 5.2 W. COUNCIL, Adams, ID

Built 2001 Load: 23.6 t ADT: 50

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

FDR

Good

Over: EAST FORK WOOD RIVER

8 MILES SE OF KETCHUM, Blaine, ID

Built 1974 Load: 23.7 t ADT: 50

FOREST ROAD 1875

Good

Over: RAINY DAY CREEK

NO DATA ENTERED, Idaho, ID

Built 1972 Load: 23.7 t ADT: 40

FS ROUTE NO. 301

Good

Over: MERRY CREEK

1.1 MILE FROM CLARKIA, ID, Shoshone, ID

Built 1954 Load: 23.7 t ADT: 40

FS ROUTE 280

Good

Over: GROUSE CREEK

8 MILES NW OF COLBURN ID, Bonner, ID

Built 1987 Load: 24.0 t ADT: 40

Showing 1,101-1,150 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.

Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.