Total bridges
182
Public highway bridges in Jefferson County
County profile · official public datasets
182 public highway bridges tracked in the FHWA National Bridge Inventory: 57.1% rated Good, 37.4% Fair, 5.5% Poor.
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.
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.
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
Share of 182 NBI-tracked bridges by lowest applicable component rating.
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.
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.
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.
182 bridges with a recorded construction year, grouped by decade
1920–1929
1 bridges
1930–1939
8 bridges
1940–1949
5 bridges
1950–1959
12 bridges
1960–1969
33 bridges
1970–1979
7 bridges
1980–1989
14 bridges
1990–1999
25 bridges
2000–2009
25 bridges
2010–2019
44 bridges
2020–2029
8 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).
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Columbia County | 183 | 30.1% | 63.9% | 6% | 1977 |
| Portage County | 182 | 53.3% | 44% | 2.7% | 1991 |
| Jefferson County (this page) | 182 | 57.1% | 37.4% | 5.5% | 1987 |
| 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 Jefferson County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Jefferson County, both outside Wisconsin so the neighborhoods are not the same-state size table above.
Nearest county inventories outside WI (182 bridges here).
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.
Over: STH 26
1.7M N JCT USH 12, Jefferson, WI
Over: ROCK RIVER
CITY OF JEFFERSON, Jefferson, WI
Over: LRD WATERTOWN STREET
7.4M E JCT STH 89 TO N, Jefferson, WI
Over: LRD WATERTOWN ST
0.3M W JCT STH 26, Jefferson, WI
Over: KOSHKONONG CR
1.7M S JCT CTH B, Jefferson, WI
Over: OCONOMOWOC RIVER
0.3M E JCT CTH E, Jefferson, WI
Over: LRD N HIGH STREET (CTH K
0.4 MI N OF JCT STH 89, Jefferson, WI
Over: ROCK R
0.6 MI. N IF CTH Y, Jefferson, WI
Over: ROCK R
0.6 MI. N OF CTH Y, Jefferson, WI
Over: STH 106
1.65 MI. S OF USH 12, Jefferson, WI
Over: ROCK CREEK
1.2 MILES EAST JCT. STH 8, Jefferson, WI
Over: LRD BLACKHAWK ISLAND ROA
1.6M S JCT STH 106, Jefferson, WI
Over: MAUNESHA RIVER
0.3M N JCT STH 89, Jefferson, WI
Over: MAUNESHA RIVER
0.1M E JCT STH 89 TO N, Jefferson, WI
Over: STH 26
0.2M N JCT STH 26, Jefferson, WI
Over: STH 16
2.5 MI. N OF CTH F, Jefferson, WI
Over: MAUNESHA RIVER
4.1M E JCT STH 73 TO N, Jefferson, WI
Over: STH 26
2.0M W JCT CTH X, Jefferson, WI
Over: ROCK CR
1.2M E JCT FAVILLE RD, Jefferson, WI
Over: LRD N HIGH STREET (CTH K
3.9 M S JCT USH 18, Jefferson, WI
Over: LRD HILLSIDE RD
2.9M W JCT CTH F TO N, Jefferson, WI
Over: ROCK RIVER
3.9M N JCT CTH K TO N, Jefferson, WI
Over: MAUNESHA RIVER
0.3 MI W JCT STH 89, Jefferson, WI
Over: TRIBUTARY TO ROCK RIVER
500 FT E JCT FALK RD, Jefferson, WI
Over: CRAWFISH RIVER
0.3M S JCT USH 18, Jefferson, WI
Over: STH 106
2.5M N JCT STH B 26, Jefferson, WI
Over: KOSHKONONG CREEK
0.3M E JCT STH 134, Jefferson, WI
Over: BARK RIVER
1.0M E JCT CTH D, Jefferson, WI
Over: STH 26
0.8 MI. S OF BUS. 26, Jefferson, WI
Over: STH 19
AT STH 19, Jefferson, WI
Over: STH 19
AT STH 19, Jefferson, WI
Over: BARK RIVER
0.3M E JCT CTH D TO S, Jefferson, WI
Over: CTH P
3.8M W JCT CTH F TO N, Jefferson, WI
Over: JOHNSON CREEK
0.2M N JCT CTH Y, Jefferson, WI
Over: BARK RIVER
0.4M E JCT CTH D, Jefferson, WI
Over: JOHNSON CREEK
0.4M W JCT STH 26, Jefferson, WI
Over: CTH CW
0.8M E JCT CTH R, Jefferson, WI
Over: DUCK CREEK
1.3M E JCT CTH D, Jefferson, WI
Over: ROCK RIVER
0.7M S JCT STH 19, Jefferson, WI
Over: ROCK RIVER
1.0M N JCT CTH Y TO E, Jefferson, WI
Over: CTH OCONOMOWOC RIVER
0.7M N JCT IH 94 TO E, Jefferson, WI
Over: ROCK RIVER
0.6M S JCT STH 19, Jefferson, WI
Over: ROCK R
0.3 MI. N OF OLD CTH Y, Jefferson, WI
Over: LRD UNION ST
0.9M W JCT STH 26 TO N, Jefferson, WI
Over: MAUNESHA RIVER
3.4M E JCT STH 73 TO N, Jefferson, WI
Over: STH 16
1.3M W OF CL ALONG STH 16, Jefferson, WI
Over: TRIB TO ROCK RIVER
0.2 MI. SOUTH OF STH 26 O, Jefferson, WI
Over: ROCK R
2.3M N JCT USH 18, Jefferson, WI
Over: ROCK RIVER
2.3M N JCT USH 18, Jefferson, WI
Over: LRD S MAIN STREET
2.1 MI S OF JUNC USH 18, Jefferson, WI
Read our methodology - how this data is sourced, computed, and verified.
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.