County profile · official public datasets

Grant County, WI

383 public highway bridges tracked in the FHWA National Bridge Inventory: 66.1% rated Good, 29.5% Fair, 4.4% Poor.

383
Public bridges
66.1%
Good condition
4.4%
Poor condition

The verdict

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

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

Top 32%
lowest Poor share in state
4.4%
Poor-condition share
383
public highway bridges
1984
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.

Grant County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Grant County ranks #23 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.4%). Grant County, Wisconsin contains 383 public highway bridges. Roughly 66.1% are rated “Good,” 29.5% “Fair,” and 4.4% “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

383

Public highway bridges in Grant County

Good condition

66.1%

253 of 383 rated 7-9

Fair condition

29.5%

113 of 383 rated 5-6

Poor condition

4.4%

17 of 383 rated 4 or below

In-state Poor-share rank

#23 of 72

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

Condition distribution

Share of 383 NBI-tracked bridges by lowest applicable component rating.

Good
66.1% (253)
Fair
29.5% (113)
Poor
4.4% (17)

Grant County's Poor-condition bridges carry 5,024 vehicle crossings a day

That is 1.4% of the county's reported daily bridge traffic on 4.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 296 crossings a day against 871 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 383 of 383 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

28.5% of Grant County's bridges have passed the 50-year mark

109 of the 383 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 66.1% 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 23.9% of the county's Poor-condition bridge traffic

CTH T over WISCONSIN RIVER 03, built 1958, carries 1,200 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 17-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,024 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Grant County's bridges were built

383 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1990s, when 75 of the county's bridges still in the inventory were built, which is 19.6% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1984) matches the Wisconsin average (1984).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Wisconsin counties nearest Grant County in number of bridges, with their condition splits. Its 4.4% Poor share is the 2nd-lowest of these 6. Its average build year of 1984 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 Grant County and the 5 Wisconsin counties closest to it in inventory size
County Bridges Poor
Grant County (this page) 383 4.4%
Monroe County 374 3.5%
Waukesha County 369 6.5%
Chippewa County 359 9.2%
Vernon County 333 7.5%
Barron County 319 5.6%

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

Similar inventory size

Nearest county inventories outside WI (383 bridges here).

Similar average build year

Nearest mean year-built outside WI (1984 here).

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

All 383 Good 253 Fair 113 Poor 17

Good-condition bridges (253)

STH 80

Good

Over: MOUNDS BRANCH

3.4M N JCT STH 81 TO W, Grant, WI

Built 2012 Load: 35.0 t ADT: 3,000

CTH T

Good

Over: BIG GREEN RIVER

0.2M E JCT CTH K, Grant, WI

Built 2018 Load: 35.3 t ADT: 240

LRD BLUFF RD

Good

Over: BLUE RIVER

0.5M E JCT CTH J, Grant, WI

Built 1982 Load: 35.6 t ADT: 102

LRD PLATTE RD

Good

Over: PLATTE RIVER

2.0M S JCT STH 81, Grant, WI

Built 1982 Load: 35.6 t ADT: 104

CTH U

Good

Over: BR BOICE CREEK

3.25 M W JCT STH 61, Grant, WI

Built 1987 Load: 35.6 t ADT: 678

CTH J

Good

Over: LITTLE GRANT RIVER

2.8M S JCT USH 18, Grant, WI

Built 1987 Load: 35.6 t ADT: 445

LRD OLD POTOSI RD

Good

Over: BOICE CREEK

5.2M S JCT STH 81, Grant, WI

Built 1987 Load: 35.6 t ADT: 104

LRD BAKER FORD RD

Good

Over: CULVER CREEK

2.9M S JCT STH 81, Grant, WI

Built 1989 Load: 35.6 t ADT: 53

LRD BLUFF RD

Good

Over: BORAH CREEK

1.0M E JCT CTH K, Grant, WI

Built 1990 Load: 35.6 t ADT: 53

LRD ROCK CUT RD

Good

Over: MENOMINEE CREEK

0.2M N JCT STH 11, Grant, WI

Built 1990 Load: 35.6 t ADT: 172

USH 61/151 NB-STH

Good

Over: CTH HHH

4.6M N JCT STH 11 TO E, Grant, WI

Built 1993 Load: 35.6 t ADT: 7,500

LRD MORGAN RD

Good

Over: MCADAM BRANCH

1.7M N JCT CTH HH, Grant, WI

Built 1992 Load: 35.6 t ADT: 103

CTH A

Good

Over: PLATTE RIVER

4.2M W JCT CTH D, Grant, WI

Built 1994 Load: 35.6 t ADT: 499

LRD YORK RD

Good

Over: BR SINSINAWA RIVER

2.4M W JCT STH 80, Grant, WI

Built 1996 Load: 35.6 t ADT: 80

LRD KUSSMAUL RD

Good

Over: WARNER CREEK

0.4M S JCT CTH C, Grant, WI

Built 1998 Load: 35.6 t ADT: 102

CTH N

Good

Over: GRANT RIVER

1.4M N JCT STH 133, Grant, WI

Built 1999 Load: 35.6 t ADT: 352

CTH T

Good

Over: BLUE RIVER

0.6M N JCT STH 133, Grant, WI

Built 2001 Load: 35.6 t ADT: 1,505

USH 151 NB

Good

Over: LRD MC ADAM RD

1.1M N JCT CTH HH, Grant, WI

Built 2005 Load: 35.6 t ADT: 8,100

USH 61

Good

Over: CROOKED CREEK

5.4M N JCT CTH T, Grant, WI

Built 2002 Load: 35.6 t ADT: 4,000

LRD MINERAL ST

Good

Over: ROUNDTREE BRANCH

0.3M W JCT USH 151, Grant, WI

Built 2002 Load: 35.6 t ADT: 3,210

CTH U (BEETOWN SC

Good

Over: BEETOWN BRANCH

0.3M N JCT STH 81, Grant, WI

Built 2003 Load: 35.6 t ADT: 740

USH 151

Good

Over: ROUNDTREE BRANCH CREEK

0.2M N JCT STH 80, Grant, WI

Built 2005 Load: 35.6 t ADT: 9,495

LRD LINK RD

Good

Over: ROGERS BRANCH

0.8M W JCT USH 61, Grant, WI

Built 2006 Load: 35.6 t ADT: 105

LRD SHADY HOLLOW L

Good

Over: DRY RUN

0.2 MI NORTH OF ROSENDALE, Grant, WI

Built 2014 Load: 35.6 t ADT: 100

LRD IRISH HOLLOW R

Good

Over: MARLOW BR

1.3M N JCT CTH U, Grant, WI

Built 1988 Load: 35.6 t ADT: 78

STH 133

Good

Over: LITTLE GREEN RIVER

4.1M N JCT USH 18 TO E, Grant, WI

Built 2010 Load: 36.0 t ADT: 630

LRD LOST HOLLOW RD

Good

Over: LITTLE GREEN RIVER

1.3M E JCT STH 133, Grant, WI

Built 2009 Load: 36.0 t ADT: 102

LRD CTH C

Good

Over: MILLVILLE CREEK

6 MILES EAST OF US 18, Grant, WI

Built 2009 Load: 36.0 t ADT: 288

LRD BORAH ROAD

Good

Over: BORAH CREEK

2.6M E JCT CTH K, Grant, WI

Built 2021 Load: 36.0 t ADT: 100

LRD CHESTNUT STREE

Good

Over: ROUNTREE BRANCH

0.15 MI N JCT BUS HWY 151, Grant, WI

Built 2010 Load: 36.3 t ADT: 2,562

LRD BREWERY HOLLOW

Good

Over: POTOSI BRANCH

0.1M E JCT STH 133, Grant, WI

Built 2021 Load: 36.3 t ADT: 270

LRD AIRPORT RD

Good

Over: PLATTE RIVER

3.3 MI E OF JCT USH 61, Grant, WI

Built 2014 Load: 36.6 t ADT: 75

LRD SHEMACK RD

Good

Over: TRIB TO BLUE RIVER

0.9 MI S JCT CTH Q, Grant, WI

Built 2021 Load: 36.6 t ADT: 100

CTH K

Good

Over: BIG GREEN RIVER

.6 MILES S. JCT STH 133, Grant, WI

Built 2014 Load: 36.9 t ADT: 170

LRD CHAFFIE HOLLOW

Good

Over: GRANT RIVER

1.8M N JCT STH 133, Grant, WI

Built 1982 Load: 37.3 t ADT: 104

LRD PIGEON RIVER R

Good

Over: GRANT RIVER

0.3M E JCT CTH U, Grant, WI

Built 1986 Load: 37.3 t ADT: 59

LRD GOVIER RD

Good

Over: LITTLE GRANT RIVER

1.0M N JCT CTH A, Grant, WI

Built 1988 Load: 37.3 t ADT: 102

LRD DRY HOLLOW RD

Good

Over: BACON BRANCH

0.5M N JCT CTH A, Grant, WI

Built 1989 Load: 37.3 t ADT: 104

USH 61/151 SB-STH

Good

Over: CTH HHH

2.7M S JCT CTH HH TO E, Grant, WI

Built 1994 Load: 37.3 t ADT: 7,500

LRD PIGEON RIVER R

Good

Over: PIGEON RIVER

2.3M W JCT CTH N, Grant, WI

Built 1992 Load: 37.3 t ADT: 161

LRD ADRIAN HOLLOW

Good

Over: BR GRANT RIVER

1.4M N JCT STH 133, Grant, WI

Built 1992 Load: 37.3 t ADT: 53

LRD TOWNLINE RD

Good

Over: BR PLATTE RIVER

3.0M S JCT USH 18, Grant, WI

Built 1994 Load: 37.3 t ADT: 53

LRD COLLINS RD

Good

Over: BIG GREEN RIVER

0.3M S JCT CTH K, Grant, WI

Built 1994 Load: 37.3 t ADT: 53

CTH Q

Good

Over: FENNIMORE CREEK

5.7M N JCT USH 18, Grant, WI

Built 1994 Load: 37.3 t ADT: 519

CTH Q

Good

Over: SIX MILE BRANCH

1.5M S JCT CTH G, Grant, WI

Built 1996 Load: 37.3 t ADT: 153

LRD HOMER RD

Good

Over: FENNIMORE CREEK

0.3M N JCT CTH Q, Grant, WI

Built 1996 Load: 37.3 t ADT: 104

STH 133

Good

Over: TRIB TO WISCONSIN RIVER

5.1M N JCT USH 61 TO N, Grant, WI

Built 1999 Load: 37.3 t ADT: 2,500

STH 133

Good

Over: TRIB TO WISCONSIN RIVER

6.0M N JCT USH 61 TO N, Grant, WI

Built 1999 Load: 37.3 t ADT: 2,500

STH 133

Good

Over: TRIB TO WISCONSIN RIVER

6.4M N JCT USH 61 TO N, Grant, WI

Built 1999 Load: 37.3 t ADT: 2,500

CTH B

Good

Over: PLATTE RIVER

2.3M E JCT STH 35, Grant, WI

Built 1999 Load: 37.3 t ADT: 1,325

Read our methodology - how this data is sourced, computed, and verified.

Related

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.