County profile · official public datasets

Columbia County, WI

183 public highway bridges tracked in the FHWA National Bridge Inventory: 30.1% rated Good, 63.9% Fair, 6% Poor.

183
Public bridges: 30.1%
Good condition: 6%
Poor condition

The verdict

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

Columbia County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

38th
of 72 on Poor share: 6%
Poor-condition share: 183
public highway bridges: 1977
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.

Columbia County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Columbia County ranks #38 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6%). Columbia County, Wisconsin contains 183 public highway bridges. Roughly 30.1% are rated “Good,” 63.9% “Fair,” and 6% “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

183

Public highway bridges in Columbia County

Good condition

30.1%

55 of 183 rated 7-9

Fair condition

63.9%

117 of 183 rated 5-6

Poor condition

11 of 183 rated 4 or below

In-state Poor-share rank

#38 of 72

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

Condition distribution

Share of 183 NBI-tracked bridges by lowest applicable component rating.

Good

30.1% (55)

Fair

63.9% (117)

Poor

6% (11)

Columbia County's Poor-condition bridges carry 2,132 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 194 crossings a day against 4,801 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 183 of 183 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

51.9% of Columbia County's bridges have passed the 50-year mark

95 of the 183 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 30.1% 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 23.5% of the county's Poor-condition bridge traffic

CTH CM over FOX RIVER, built 1958, carries 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 2,132 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

1
1920s

1
1930s

7
1940s

3
1950s

20
1960s

55
1970s

16
1980s

6
1990s

32
2000s

19
2010s

13
2020s

8

What this shows Construction peaked in the 1960s, when 55 of the county's bridges still in the inventory were built, which is 30.1% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1977, 7 years older than the Wisconsin average of 1984.

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

The 5 Wisconsin counties nearest Columbia County in number of bridges, with their condition splits. Its 6% Poor share is the 5th-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1986 is 9 years older.

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

Bridge inventory size and condition shares for Columbia County and the 5 Wisconsin counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Columbia County (this page)	183	30.1%	63.9%	6%	1977
Jefferson County	182	57.1%	37.4%	5.5%	1987
Portage County	182	53.3%	44%	2.7%	1991
Taylor County	176	58.5%	30.1%	11.4%	1988
Juneau County	172	49.4%	47.7%	2.9%	1981
Waupaca County	169	76.3%	20.7%	3%	1984

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

Similar inventory size

Nearest county inventories outside WI (183 bridges here).

St. Clair County, AL · 183 bridges
Richmond County, GA · 183 bridges
Marshall County, IN · 183 bridges
Appanoose County, IA · 183 bridges

Similar average build year

Nearest mean year-built outside WI (1977 here).

San Diego County, CA · avg 1977 · 1,632 bridges
King County, WA · avg 1977 · 1,238 bridges
Riverside County, CA · avg 1977 · 1,117 bridges
Shelby County, TN · avg 1977 · 1,077 bridges

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

All 183 Good 55 Fair 117 Poor 11

Good-condition bridges (55)

Sort:

Columbia County Bridge Snapshot

Condition distribution

Columbia County's Poor-condition bridges carry 2,132 vehicle crossings a day

51.9% of Columbia County's bridges have passed the 50-year mark

One structure carries 23.5% of the county's Poor-condition bridge traffic

How Columbia 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 (55)

CTH CD

LRD FALL RIVER RD

STH 60

IH 90 WB-IH 94 WB

USH 151

STH 16

STH 60

STH 113

CTH V NB

CTH V NB

STH 22-N MAIN ST

STH 22-WASHINGTON

USH 151 NB

CTH U

LRD SAUER RD

LRD FAIR ST

USH 51

STH 16 E

LRD ILLINOIS AVE

CTH U

LRD WENDT ROAD

CTH U

IH 39 NB

STH 78 SB

STH 113

STH 33

CTH D MAIN ST

LRD HALL RD

CTH N

CTH SS

LRD RIVER RD (OLD

USH 151 NB

STH NB/EB STH 13/1

STH 22-WASHINGTON

CTH CS

CTH P

IH 39/90/94 NB

LRD CLARK ROAD

CTH M

STH 113

STH 127

USH 151 SB

IH 39

CTH Z

USH 51

USH 151 SB

LRD DUBORG RD

LRD BLACK RD

LRD HAYNES RD

LRD HALL ROAD

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