County profile · official public datasets

Manitowoc County, WI

269 public highway bridges tracked in the FHWA National Bridge Inventory: 44.6% rated Good, 51.7% Fair, 3.7% Poor.

269
Public bridges: 44.6%
Good condition: 3.7%
Poor condition

The verdict

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

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

Top 24%
lowest Poor share in state: 3.7%
Poor-condition share: 269
public highway bridges: 1983
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.

Manitowoc County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Manitowoc County ranks #17 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.7%). Manitowoc County, Wisconsin contains 269 public highway bridges. Roughly 44.6% are rated “Good,” 51.7% “Fair,” and 3.7% “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

269

Public highway bridges in Manitowoc County

Good condition

44.6%

120 of 269 rated 7-9

Fair condition

51.7%

139 of 269 rated 5-6

Poor condition

3.7%

10 of 269 rated 4 or below

In-state Poor-share rank

#17 of 72

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

Condition distribution

Share of 269 NBI-tracked bridges by lowest applicable component rating.

Good

44.6% (120)

Fair

51.7% (139)

Poor

3.7% (10)

Manitowoc County's Poor-condition bridges carry 13,785 vehicle crossings a day

That is 1.4% of the county's reported daily bridge traffic on 3.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,379 crossings a day against 2,358 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 269 of 269 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

26.4% of Manitowoc County's bridges have passed the 50-year mark

71 of the 269 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 44.6% 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 23.2% of the county's Poor-condition bridge traffic

STH 32-STH 57 over SHEBOYGAN RIVER, built 1958, carries 3,200 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 10-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 13,785 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

2
1920s

6
1930s

8
1940s

4
1950s

11
1960s

21
1970s

100
1980s

26
1990s

19
2000s

26
2010s

32
2020s

13

What this shows Construction peaked in the 1970s, when 100 of the county's bridges still in the inventory were built, which is 37.2% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1983) matches the Wisconsin average (1984).

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

The 5 Wisconsin counties nearest Manitowoc County in number of bridges, with their condition splits. Its 3.7% Poor share is the 2nd-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1986 is in line with the group.

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

Bridge inventory size and condition shares for Manitowoc County and the 5 Wisconsin counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Sauk County	271	53.9%	37.3%	8.9%	1984
Manitowoc County (this page)	269	44.6%	51.7%	3.7%	1983
Winnebago County	263	66.9%	29.7%	3.4%	1992
Trempealeau County	260	47.3%	41.2%	11.5%	1987
Fond du Lac County	251	53%	36.7%	10.4%	1986
La Crosse County	249	41%	53%	6%	1983

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

Similar inventory size

Nearest county inventories outside WI (269 bridges here).

Grundy County, IL · 269 bridges
Bartholomew County, IN · 269 bridges
Rensselaer County, NY · 269 bridges
Harrison County, TX · 269 bridges

Similar average build year

Nearest mean year-built outside WI (1983 here).

Dallas County, TX · avg 1983 · 3,230 bridges
Bexar County, TX · avg 1983 · 2,342 bridges
Sedgwick County, KS · avg 1983 · 1,333 bridges
Will County, IL · avg 1983 · 649 bridges

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

All 269 Good 120 Fair 139 Poor 10

Fair-condition bridges (139)

Sort:

Manitowoc County Bridge Snapshot

Condition distribution

Manitowoc County's Poor-condition bridges carry 13,785 vehicle crossings a day

26.4% of Manitowoc County's bridges have passed the 50-year mark

One structure carries 23.2% of the county's Poor-condition bridge traffic

How Manitowoc 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 (139)

IH 43 SB

LRD COUNTY LINE RD

LRD 18TH ST

IH 43 NB

CTH X

IH 43 SB

LRD SILVER CREEK R

IH 43 SB-STH 42 SB

IH 43 SB

USH 10 W

USH 10 EB

LRD REVERE DR (SB)

LRD NORTH 21ST STR

LRD LAKE SHORE RD

LRD STURM RD

IH 43 SB -STH 42 S

IH 43 NB-STH 42 NB

IH 43 SB

IH 43 NB

IH 43 SB

IH 43 SB

LRD BROADWAY STREE

LRD MILL STREET

STH 42

LRD S UNION RD

LRD DAIRYLAND DR

CTH V

CTH R

IH 43

LRD S CLEVELAND RD

CTH C

IH 43

IH 43

IH 43

STH 67

IH 43

LRD FISCHERVILLE R

LRD GREENSTREET RD

IH 43 NB

IH 43 NB

IH 43 NB

STH 147

LRD GRIMMS RD

LRD LAKE SHORE RD

CTH CL VIEBAHN S

IH 43 NB

IH 43 SB

IH 43 NB

LRD TISCH MILLS RD

USH 10-MAIN ST

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