County profile · official public datasets

Kootenai County, ID

154 public highway bridges tracked in the FHWA National Bridge Inventory: 31.2% rated Good, 65.6% Fair, 3.2% Poor.

154
Public bridges: 31.2%
Good condition: 3.2%
Poor condition

The verdict

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

Kootenai County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 39%
lowest Poor share in state: 3.2%
Poor-condition share: 154
public highway bridges: 1984
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.

Kootenai County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Kootenai County ranks #17 of 44 Idaho counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.2%). Kootenai County, Idaho contains 154 public highway bridges. Roughly 31.2% are rated “Good,” 65.6% “Fair,” and 3.2% “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

154

Public highway bridges in Kootenai County

Good condition

31.2%

48 of 154 rated 7-9

Fair condition

65.6%

101 of 154 rated 5-6

Poor condition

3.2%

5 of 154 rated 4 or below

In-state Poor-share rank

#17 of 44

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

Condition distribution

Share of 154 NBI-tracked bridges by lowest applicable component rating.

Good

31.2% (48)

Fair

65.6% (101)

Poor

3.2% (5)

Kootenai County's Poor-condition bridges carry 32,770 vehicle crossings a day

That is 2.5% of the county's reported daily bridge traffic on 3.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 6,554 crossings a day against 5,800 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 154 of 154 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

37.7% of Kootenai County's bridges have passed the 50-year mark

58 of the 154 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 31.2% 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 96.1% of the county's Poor-condition bridge traffic

I 90 WBL over PEDESTRIAN/BIKE PATH, built 1971, carries 31,500 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 5-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 32,770 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

1
1930s

2
1940s

2
1950s

15
1960s

27
1970s

29
1980s

13
1990s

14
2000s

24
2010s

16
2020s

11

What this shows Construction peaked in the 1970s, when 29 of the county's bridges still in the inventory were built, which is 18.8% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1984, 5 years newer than the Idaho average of 1979.

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

The 5 Idaho counties nearest Kootenai County in number of bridges, with their condition splits. Its 3.2% Poor share is the 3rd-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1978 is 6 years newer.

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

Bridge inventory size and condition shares for Kootenai County and the 5 Idaho counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kootenai County (this page)	154	31.2%	65.6%	3.2%	1984
Valley County	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 Kootenai 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 Kootenai County, both outside Idaho so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside ID (154 bridges here).

Choctaw County, AL · 154 bridges
Arkansas County, AR · 154 bridges
Elk County, KS · 154 bridges
Madison County, KY · 154 bridges

Similar average build year

Nearest mean year-built outside ID (1984 here).

Hennepin County, MN · avg 1984 · 936 bridges
Duval County, FL · avg 1984 · 831 bridges
El Paso County, CO · avg 1984 · 686 bridges
Bell County, TX · avg 1984 · 660 bridges

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

All 154 Good 48 Fair 101 Poor 5

Fair-condition bridges (101)

Sort:

Kootenai County Bridge Snapshot

Condition distribution

Kootenai County's Poor-condition bridges carry 32,770 vehicle crossings a day

37.7% of Kootenai County's bridges have passed the 50-year mark

One structure carries 96.1% of the county's Poor-condition bridge traffic

How Kootenai 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

Fair-condition bridges (101)

I 90 WBL

SH 3

I 90 EBL

I 90 WBL

I 90 WBL

I 90 EBL

I 90 WBL

I 90 EBL

I 90 WBL

9TH ST

MCGUIRE RD

I 90 EBL

I 90 WBL

I 90 EBL

I 90 WBL

IDAHO ROAD

W POIRER ROAD

I 90 WBL

I 90RAMP EB OFF

I 90 EBL

STC 7185;APPLEWAY

STC 5736;HAYDEN LK

I 90

YELLOWSTONE TRAIL

SMA7235;NW BLVD

FS ROUTE N0. 812

FS ROUTE NO. 437

I 90 EB-WB;RMP CD

US 95

SH 58

LOFFS BAY ROAD

HAYDEN LAKE ROAD

SH 3

US 95

CATALDO MISSION RD

I 90

US 95

ALDER CREEK RD

US 95 SBL

I 90

SH 41

SMA7605:SELTICE WY

SH 3

SMA 7155;GOVT WAY

STP7605;SELTICE WY

I 90

US 95

FS ROUTE NO. 209

I 90 EBL & WBL

I 90 EBL & WBL

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