County profile · official public datasets

Valley County, ID

149 public highway bridges tracked in the FHWA National Bridge Inventory: 45% rated Good, 48.3% Fair, 6.7% Poor.

149
Public bridges: 45%
Good condition: 6.7%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Valley County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

32nd
of 44 on Poor share: 6.7%
Poor-condition share: 149
public highway bridges: 1982
avg year built

Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.

Valley County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Valley County ranks #32 of 44 Idaho counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.7%). Valley County, Idaho contains 149 public highway bridges. Roughly 45% are rated “Good,” 48.3% “Fair,” and 6.7% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

Total bridges

149

Public highway bridges in Valley County

Good condition

45%

67 of 149 rated 7-9

Fair condition

48.3%

72 of 149 rated 5-6

Poor condition

6.7%

10 of 149 rated 4 or below

In-state Poor-share rank

#32 of 44

Among Idaho counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 149 NBI-tracked bridges by lowest applicable component rating.

Good

45% (67)

Fair

48.3% (72)

Poor

6.7% (10)

Valley County's Poor-condition bridges carry 5,090 vehicle crossings a day

That is 6.1% of the county's reported daily bridge traffic on 6.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 509 crossings a day against 233 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.

Computed over the 149 of 149 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

38.9% of Valley County's bridges have passed the 50-year mark

58 of the 149 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 45% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.

Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.

One structure carries 82.5% of the county's Poor-condition bridge traffic

SH 55 over UPRR;N.FK.PAYETTE RIVER, built 1933, carries 4,200 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 10-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,090 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

1
1920s

1
1930s

5
1940s

6
1950s

14
1960s

27
1970s

22
1980s

14
1990s

14
2000s

17
2010s

24
2020s

4

What this shows Construction peaked in the 1960s, when 27 of the county's bridges still in the inventory were built, which is 18.1% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1982) matches the Idaho average (1979).

How Valley County compares with Idaho's closest counties by inventory size

The 5 Idaho counties nearest Valley County in number of bridges, with their condition splits. Its 6.7% Poor share is the 5th-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1978 is in line with the group.

Showing the 5 closest of 43 Idaho counties eligible for comparison.

Bridge inventory size and condition shares for Valley County and the 5 Idaho counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kootenai County	154	31.2%	65.6%	3.2%	1984
Valley County (this page)	149	45%	48.3%	6.7%	1982
Fremont County	137	32.8%	61.3%	5.8%	1983
Custer County	128	34.4%	56.3%	9.4%	1978
Jefferson County	127	17.3%	79.5%	3.1%	1973
Twin Falls County	126	12.7%	84.1%	3.2%	1973

Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Valley County's. Source: FHWA National Bridge Inventory, 2024 release.

Nationwide counties with similar inventory size or average build year

Two NBI-derived peer sets for Valley County, both outside Idaho so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside ID (149 bridges here).

Tallapoosa County, AL · 149 bridges
Drew County, AR · 149 bridges
Madison County, AR · 149 bridges
Walker County, GA · 149 bridges

Similar average build year

Nearest mean year-built outside ID (1982 here).

Oklahoma County, OK · avg 1982 · 1,216 bridges
Jackson County, MO · avg 1982 · 930 bridges
Milwaukee County, WI · avg 1982 · 893 bridges
Champaign County, IL · avg 1982 · 727 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 149 Good 67 Fair 72 Poor 10

All bridges (149)

Sort:

Valley County Bridge Snapshot

Condition distribution

Valley County's Poor-condition bridges carry 5,090 vehicle crossings a day

38.9% of Valley County's bridges have passed the 50-year mark

One structure carries 82.5% of the county's Poor-condition bridge traffic

How Valley County compares with Idaho's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (149)

STC3907; DEINHARD

STC3895;YELLOWPINE

LICK CREEK ROAD

SILVER CK. SMT. RD

SILVER CK. SMT. RD

STIBNITE ROAD

EASTSIDE DRIVE

BIG CREEK ROAD

STC 3988;ROSEBERRY

STC 3800;CARBARTON

STC3906;WARREN WGN

WHITEHAWK L.O. RD.

SILVER CREEK ROAD

LICK CREEK ROAD

NO MAN ROAD

SH 55

AIRPORT ACCESS RD

BIG CREEK ROAD

S FK SALMON

S3945;EAST LAKE FK

NFSR 50446

NFSR 421

DITCH CREEK RD

S FK OF SALMON RIV

PARADISE VALLEY RO

THUNDER MT RD

STC3906;WARREN WGN

EAGLE NEST-GOLD FK

LICK CREEK ROAD

ROUND VALLEY RD

NORWOOD RD

STC 3938;ROSEBERRY

STC3895;JOHNSON CR

DAGGER FALLS ROAD

EASTSIDE DRIVE

NO DATA ENTERED

EAST FORK ROAD

ELK SUMMIT RD

CLEAR CREEK ROAD

ELK SUMMIT RD

ROAD 50343

SMITH FERRY DRIVE

SH 55

EAST FORK ROAD

BURNT LOG ROAD

LICK CREEK RD

PADDY FLAT ROAD

STC 3988;ROSEBERRY

NISULA ROAD

Related