County profile · official public datasets

Monroe County, WI

374 public highway bridges tracked in the FHWA National Bridge Inventory: 50.5% rated Good, 46% Fair, 3.5% Poor.

374
Public bridges: 50.5%
Good condition: 3.5%
Poor condition

The verdict

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

Monroe County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 17%
lowest Poor share in state: 3.5%
Poor-condition share: 374
public highway bridges: 1981
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.

Monroe County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Monroe County ranks #12 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.5%). Monroe County, Wisconsin contains 374 public highway bridges. Roughly 50.5% are rated “Good,” 46% “Fair,” and 3.5% “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

374

Public highway bridges in Monroe County

Good condition

50.5%

189 of 374 rated 7-9

Fair condition

46%

172 of 374 rated 5-6

Poor condition

3.5%

13 of 374 rated 4 or below

In-state Poor-share rank

#12 of 72

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

Condition distribution

Share of 374 NBI-tracked bridges by lowest applicable component rating.

Good

50.5% (189)

Fair

46% (172)

Poor

3.5% (13)

Monroe County's Poor-condition bridges carry 19,681 vehicle crossings a day

That is 1.6% of the county's reported daily bridge traffic on 3.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,514 crossings a day against 3,276 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 374 of 374 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

39% of Monroe County's bridges have passed the 50-year mark

146 of the 374 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 50.5% 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 66.8% of the county's Poor-condition bridge traffic

IH 94 EB over RAMP IH 90EB-IH 94WB, built 1963, carries 13,150 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 13-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 19,681 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

1
1920s

17
1930s

24
1940s

7
1950s

12
1960s

72
1970s

39
1980s

36
1990s

66
2000s

45
2010s

44
2020s

10

What this shows Construction peaked in the 1960s, when 72 of the county's bridges still in the inventory were built, which is 19.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1981) matches the Wisconsin average (1984).

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

The 5 Wisconsin counties nearest Monroe County in number of bridges, with their condition splits. Its 3.5% Poor share is the 1st-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1983 is in line with the group.

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

Bridge inventory size and condition shares for Monroe County and the 5 Wisconsin counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Grant County	383	66.1%	29.5%	4.4%	1984
Monroe County (this page)	374	50.5%	46%	3.5%	1981
Waukesha County	369	53.1%	40.4%	6.5%	1984
Chippewa County	359	34.8%	56%	9.2%	1985
Vernon County	333	44.1%	48.3%	7.5%	1983
Barron County	319	48.6%	45.8%	5.6%	1978

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

Similar inventory size

Nearest county inventories outside WI (374 bridges here).

Benton County, IA · 374 bridges
Baltimore city County, MD · 374 bridges
Rankin County, MS · 374 bridges
Cape Girardeau County, MO · 374 bridges

Similar average build year

Nearest mean year-built outside WI (1981 here).

Franklin County, OH · avg 1981 · 922 bridges
Greenville County, SC · avg 1981 · 635 bridges
Montgomery County, OH · avg 1981 · 632 bridges
McLean County, IL · avg 1981 · 624 bridges

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

All 374 Good 189 Fair 172 Poor 13

Fair-condition bridges (172)

Sort:

Monroe County Bridge Snapshot

Condition distribution

Monroe County's Poor-condition bridges carry 19,681 vehicle crossings a day

39% of Monroe County's bridges have passed the 50-year mark

One structure carries 66.8% of the county's Poor-condition bridge traffic

How Monroe 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

Fair-condition bridges (172)

LRD INDEPENDENCE R

LRD GROTTO AVE (DE

CTH BC

CTH Z

IH 94 WB

IH 94

STH 131

CTH ET

CTH XX

CTH M

LRD E OAK ST

LRD MASCOT AVE

LRD NORDALE AVE

LRD INSHORE AVE (D

LRD GLIDER AVE

STH 173

IH RAMP IH 90 EB-I

STH 131

USH 12-STH 16

LRD NIAGARA AVE

USH 12

LRD EAST AVE

STH 71

LRD ICARUS RD

LRD MASCOT AVE

LRD EAST AVE

STH 33

CTH X

LRD INTERIOR RD

LRD INDIGO AVE

CTH CA

CTH M

LRD EAST MAIN STRE

STH 71

STH 71

CTH CM

LRD FORBES RD

LRD BUCKLEY AVE

CTH Z

STH 71

IH 94 EB

LRD WATER ST

LRD GROVER ROAD

LRD HOOVER RD

LRD KILN AVE

STH 16-STH 71-WISC

LRD LANDMARK AVE

CTH S

CTH AA

LRD NOVENA RD (DEA

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