County profile · official public datasets

Jefferson County, WI

182 public highway bridges tracked in the FHWA National Bridge Inventory: 57.1% rated Good, 37.4% Fair, 5.5% Poor.

182
Public bridges
57.1%
Good condition
5.5%
Poor condition

The verdict

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

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

Top 42%
lowest Poor share in state
5.5%
Poor-condition share
182
public highway bridges
1987
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.

Jefferson County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Jefferson County ranks #30 of 72 Wisconsin counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.5%). Jefferson County, Wisconsin contains 182 public highway bridges. Roughly 57.1% are rated “Good,” 37.4% “Fair,” and 5.5% “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

182

Public highway bridges in Jefferson County

Good condition

57.1%

104 of 182 rated 7-9

Fair condition

37.4%

68 of 182 rated 5-6

Poor condition

5.5%

10 of 182 rated 4 or below

In-state Poor-share rank

#30 of 72

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

Condition distribution

Share of 182 NBI-tracked bridges by lowest applicable component rating.

Good
57.1% (104)
Fair
37.4% (68)
Poor
5.5% (10)

Jefferson County's Poor-condition bridges carry 38,940 vehicle crossings a day

That is 3.6% of the county's reported daily bridge traffic on 5.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 3,894 crossings a day against 5,496 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 182 of 182 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

34.6% of Jefferson County's bridges have passed the 50-year mark

63 of the 182 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 57.1% 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 49.2% of the county's Poor-condition bridge traffic

IH 94 WB over LRD ROCK LAKE RD, built 1965, carries 19,150 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 10-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 38,940 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Jefferson County's bridges were built

182 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 2010s, when 44 of the county's bridges still in the inventory were built, which is 24.2% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year (1987) matches the Wisconsin average (1984).

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

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

The 5 Wisconsin counties nearest Jefferson County in number of bridges, with their condition splits. Its 5.5% Poor share is the 4th-lowest of these 6. Its average build year of 1987 against a peer-group mean of 1984 is in line with the group.

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

Bridge inventory size and condition shares for Jefferson County and the 5 Wisconsin counties closest to it in inventory size
County Bridges Poor
Columbia County 183 6%
Portage County 182 2.7%
Jefferson County (this page) 182 5.5%
Taylor County 176 11.4%
Juneau County 172 2.9%
Waupaca County 169 3%

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

Similar inventory size

Nearest county inventories outside WI (182 bridges here).

Similar average build year

Nearest mean year-built outside WI (1987 here).

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

All 182 Good 104 Fair 68 Poor 10

All bridges (182)

CTH W

Good

Over: STH 26

1.5 MI S OF JUNC USH 18, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 1,700

STH 26 NB

Good

Over: USH 18

AT USH 18, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 6,500

STH 26 SB

Good

Over: USH 18

AT USH 18, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 6,500

STH 26 NB

Good

Over: LRD POPP RD

0.8 MI. N OF USH 18, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 6,200

STH 26 SB

Good

Over: LRD POPP RD

6.2 MI. S OF IH 94, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 6,200

STH 26 NB

Good

Over: LRD JEFFERSON ROAD & UPR

0.4 MI N OF CTH Y, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 4,500

STH 26 SB

Good

Over: LRD JEFFERSON ROAD AND U

3.2 MI. S OF STH 19, Jefferson, WI

Built 2010 Load: 43.7 t ADT: 4,500

STH 26 NB

Good

Over: CTH Y

AT CTH Y, Jefferson, WI

Built 2010 Load: 45.4 t ADT: 7,250

STH 26 SB

Good

Over: CTH Y

AT CTH Y, Jefferson, WI

Built 2010 Load: 45.4 t ADT: 7,250

LRD ELM RD

Good

Over: OCONOMOWOC RIVER

0.4M N JCT CTH B, Jefferson, WI

Built 2007 Load: 47.0 t ADT: 101

STH 26 SB

Good

Over: CTH N

5.2 MI. S OF IH 94, Jefferson, WI

Built 2010 Load: 47.0 t ADT: 6,200

CTH Y

Good

Over: TRIB TO ROCK RIVER

0.1 MI. SOUTH OF STH 26, Jefferson, WI

Built 2010 Load: 47.0 t ADT: 1,854

STH 26 NB

Good

Over: WISCONSIN & SOUTHERN RR

0.35 MI. N OF CTH T, Jefferson, WI

Built 2011 Load: 47.0 t ADT: 9,000

STH 26 SB

Good

Over: WISCONSIN & SOUTHERN RR

0.2 MI. S OF STH 19, Jefferson, WI

Built 2011 Load: 47.0 t ADT: 9,000

LRD KOCH RD

Good

Over: BARK RIVER

0.3M E JCT CTH D, Jefferson, WI

Built 2008 Load: 48.6 t ADT: 133

LRD HIGH RD

Good

Over: STH 26

TBD, Jefferson, WI

Built 2010 Load: 48.6 t ADT: 150

CTH A

Good

Over: STH 26

1.2 MI. N OF CTH Y, Jefferson, WI

Built 2010 Load: 48.6 t ADT: 2,400

CTH F

Good

Over: BARK RIVER

0.9M N JCT CTH P, Jefferson, WI

Built 2007 Load: 50.2 t ADT: 2,080

STH 26 NB

Good

Over: LRD BUS STH 26

2.1 MI N JUNC STH 89, Jefferson, WI

Built 2010 Load: 50.2 t ADT: 6,700

STH 26 NB

Good

Over: CTH N

2.0 MI. N OF USH 18, Jefferson, WI

Built 2010 Load: 50.2 t ADT: 6,200

STH 26 NB

Good

Over: LRD WEST STREET (CTH T)

1.9 MI. N OF CTH A, Jefferson, WI

Built 2010 Load: 53.5 t ADT: 9,000

STH 26 SB

Good

Over: LRD WEST STREET (CTH T)

0.5 MI. S OF STH 19, Jefferson, WI

Built 2010 Load: 53.5 t ADT: 9,000

LRD HAGEDORN RD

Poor

Over: DUCK CREEK

0.6M E JCT CTH D, Jefferson, WI

Built 1940 Load: 9.7 t ADT: 58

LRD WRIGHT RD

Poor

Over: JOHNSON CREEK

0.4M E JCT CTH Y, Jefferson, WI

Built 1963 Load: 11.3 t ADT: 155

CTH D

Poor

Over: BARK RIVER

3.3M N JCT STH 59, Jefferson, WI

Built 1950 Load: 19.4 t ADT: 1,500

STH 19-MAIN ST

Poor

Over: ROCK RIVER

0.1M E JCT STH 26, Jefferson, WI

Built 1931 Load: 19.4 t ADT: 15,136

LRD STAUDE RD

Poor

Over: DUCK CREEK

0.9M W JCT CTH P, Jefferson, WI

Built 1920 Load: 19.4 t ADT: 58

LRD ROCKDALE RD

Poor

Over: KOSHKONONG CREEK

1.8M N JCT STH 106, Jefferson, WI

Built 1930 Load: 19.4 t ADT: 88

LRD MORGANS RD

Poor

Over: OCONOMOWOC RIVER

1.0M N JCT CTH B, Jefferson, WI

Built 1951 Load: 19.4 t ADT: 176

CTH N

Poor

Over: DEER CREEK

1.2M N JCT STH 106, Jefferson, WI

Built 1960 Load: 19.4 t ADT: 2,537

LRD TURNER RD

Poor

Over: BARK RIVER

0.2M W JCT CTH F, Jefferson, WI

Built 1982 Load: 24.3 t ADT: 82

IH 94 WB

Poor

Over: LRD ROCK LAKE RD

1.4M W JCT STH 89 TO N, Jefferson, WI

Built 1965 Load: 30.8 t ADT: 19,150

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.