County profile · official public datasets

Polk County, NE

94 public highway bridges tracked in the FHWA National Bridge Inventory: 57.4% rated Good, 30.9% Fair, 11.7% Poor.

94
Public bridges: 57.4%
Good condition: 11.7%
Poor condition

The verdict

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

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

71st
of 88 on Poor share: 11.7%
Poor-condition share: 94
public highway bridges: 1975
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.

Polk County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Polk County ranks #71 of 88 Nebraska counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11.7%). Polk County, Nebraska contains 94 public highway bridges. Roughly 57.4% are rated “Good,” 30.9% “Fair,” and 11.7% “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

Public highway bridges in Polk County

Good condition

57.4%

54 of 94 rated 7-9

Fair condition

30.9%

29 of 94 rated 5-6

Poor condition

11.7%

11 of 94 rated 4 or below

In-state Poor-share rank

#71 of 88

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

Condition distribution

Share of 94 NBI-tracked bridges by lowest applicable component rating.

Good

57.4% (54)

Fair

30.9% (29)

Poor

11.7% (11)

Polk County's Poor-condition bridges carry 495 vehicle crossings a day

That is 1.4% of the county's reported daily bridge traffic on 11.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 45 crossings a day against 497 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 94 of 94 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

42.6% of Polk County's bridges have passed the 50-year mark

40 of the 94 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 57.4% 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 14.1% of the county's Poor-condition bridge traffic

COUNTY HIGHWAY over N BR BIG BLUE RIVER, built 1940, carries 70 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 495 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

1
1930s

14
1940s

3
1950s

6
1960s

11
1970s

15
1980s

18
1990s

10
2000s

7
2010s

5
2020s

4

What this shows Construction peaked in the 1980s, when 18 of the county's bridges still in the inventory were built, which is 19.1% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1975) matches the Nebraska average (1977).

How Polk County compares with Nebraska's closest counties by inventory size

The 5 Nebraska counties nearest Polk County in number of bridges, with their condition splits. Its 11.7% Poor share is the 5th-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1969 is 6 years newer.

Showing the 5 closest of 87 Nebraska counties eligible for comparison.

Bridge inventory size and condition shares for Polk County and the 5 Nebraska counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Frontier County	96	59.4%	20.8%	19.8%	1970
Polk County (this page)	94	57.4%	30.9%	11.7%	1975
Harlan County	92	63%	27.2%	9.8%	1969
Dawes County	91	67%	22%	11%	1965
Keith County	91	76.9%	23.1%	0%	1972
Morrill County	91	72.5%	27.5%	0%	1969

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 Polk 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 Polk County, both outside Nebraska so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside NE (94 bridges here).

Yukon-Koyukuk County, AK · 94 bridges
Lee County, AR · 94 bridges
Huerfano County, CO · 94 bridges
Henry County, KY · 94 bridges

Similar average build year

Nearest mean year-built outside NE (1975 here).

San Bernardino County, CA · avg 1975 · 1,422 bridges
Lane County, OR · avg 1975 · 1,010 bridges
Fulton County, GA · avg 1975 · 775 bridges
Westmoreland County, PA · avg 1975 · 620 bridges

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

All 94 Good 54 Fair 29 Poor 11

Good-condition bridges (54)

Sort:

Polk County Bridge Snapshot

Condition distribution

Polk County's Poor-condition bridges carry 495 vehicle crossings a day

42.6% of Polk County's bridges have passed the 50-year mark

One structure carries 14.1% of the county's Poor-condition bridge traffic

How Polk County compares with Nebraska's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Good-condition bridges (54)

FAS 2775

FAS 2775

COUNTY HIGHWAY

FAS 2740

COLL 7677

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

COUNTY HIGHWAY

N66

N92

C RD

COUNTY HIGHWAY

COUNTY HIGHWAY

135 RD

FAS 2795

COUNTY HIGHWAY

COUNTY HIGHWAY

COLL 7686

K ROAD

ROAD 137

FAS 2795

NANCE ST/FAS 2795

N39

N69

US81

COUNTY HIGHWAY

K RD

COUNTY HIGHWAY

CENTRAL STREET

NANCE STREET

NANCE STREET

US81

FAS 2775

COLL 7677

COUNTY HIGHWAY

STATE STREET

VALLEY STREET

COUNTY HIGHWAY

COLL 7686

US81/N92

COUNTY HIGHWAY

N69

N ROAD

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