County profile · official public datasets

Dunn County, WI

245 public highway bridges tracked in the FHWA National Bridge Inventory: 45.7% rated Good, 45.3% Fair, 9% Poor.

245
Public bridges: 45.7%
Good condition: 9%
Poor condition

The verdict

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

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

55th
of 72 on Poor share: 9%
Poor-condition share: 245
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.

Dunn County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Dunn County ranks #55 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9%). Dunn County, Wisconsin contains 245 public highway bridges. Roughly 45.7% are rated “Good,” 45.3% “Fair,” and 9% “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

245

Public highway bridges in Dunn County

Good condition

45.7%

112 of 245 rated 7-9

Fair condition

45.3%

111 of 245 rated 5-6

Poor condition

22 of 245 rated 4 or below

In-state Poor-share rank

#55 of 72

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

Condition distribution

Share of 245 NBI-tracked bridges by lowest applicable component rating.

Good

45.7% (112)

Fair

45.3% (111)

Poor

9% (22)

Dunn County's Poor-condition bridges carry 48,757 vehicle crossings a day

That is 5.9% of the county's reported daily bridge traffic on 9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,216 crossings a day against 3,028 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 245 of 245 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

34.7% of Dunn County's bridges have passed the 50-year mark

85 of the 245 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 45.7% 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 71.2% of the county's Poor-condition bridge traffic

IH 94 over E BR WILSON CREEK, built 1959, carries 34,700 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 22-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 48,757 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

3
1920s

2
1930s

11
1940s

10
1950s

35
1960s

20
1970s

16
1980s

42
1990s

46
2000s

32
2010s

17
2020s

11

What this shows Construction peaked in the 1990s, when 46 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 25 to 34 years old in the 2024 inventory. Its average build year (1982) matches the Wisconsin average (1984).

How Dunn County compares with Wisconsin's closest counties by inventory size

The 5 Wisconsin counties nearest Dunn County in number of bridges, with their condition splits. Its 9% Poor share is the 5th-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1982 is in line with the group.

Showing the 5 closest of 71 Wisconsin counties eligible for comparison.

Bridge inventory size and condition shares for Dunn County and the 5 Wisconsin counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Fond du Lac County	251	53%	36.7%	10.4%	1986
La Crosse County	249	41%	53%	6%	1983
Pierce County	248	64.5%	31.9%	3.6%	1984
Dunn County (this page)	245	45.7%	45.3%	9%	1982
Green County	244	45.5%	45.9%	8.6%	1978
Sheboygan County	240	39.2%	55.4%	5.4%	1979

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

Similar inventory size

Nearest county inventories outside WI (245 bridges here).

Allegany County, MD · 245 bridges
Henderson County, NC · 245 bridges
Rowan County, NC · 245 bridges
Highland County, OH · 245 bridges

Similar average build year

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

Oklahoma County, OK · avg 1982 · 1,216 bridges
Jackson County, MO · avg 1982 · 930 bridges
Champaign County, IL · avg 1982 · 727 bridges
Broward County, FL · avg 1982 · 686 bridges

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

All 245 Good 112 Fair 111 Poor 22

Good-condition bridges (112)

Sort:

Dunn County Bridge Snapshot

Condition distribution

Dunn County's Poor-condition bridges carry 48,757 vehicle crossings a day

34.7% of Dunn County's bridges have passed the 50-year mark

One structure carries 71.2% of the county's Poor-condition bridge traffic

How Dunn County compares with Wisconsin'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 (112)

CTH K

IH 94 EB

IH 94 WB

LRD 1450TH AVE

IH 94 EB

IH 94 WB

STH 79

CTH W

CTH D

IH 94 EB

IH 94 WB

IH 94 EB

IH 94 WB

CTH Q

STH 79

CTH G

STH 85

IH 94 WB

IH 94 EB

STH 79

IH 94

LRD 690TH AVE

LRD 650TH ST

LRD 330TH ST

CTH V

LRD 231ST ST

STH 40

CTH D

CTH K

LRD 730TH AVE (DEA

STH 25

CTH Q

STH 85

LRD 970TH ST

LRD 750TH AVE (DEA

CTH EE

LRD 240TH AVE

STH 64

CTH V

LRD 750TH AVE

LRD 100TH ST

LRD 210TH ST

CTH K

LRD 770TH AVE

STH 64

CTH K

STH 170

CTH Z

LRD 620TH AVE

STH 85

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