Total bridges
108
Public highway bridges in Brown County
County profile · official public datasets
Brown County, MN
108 public highway bridges tracked in the FHWA National Bridge Inventory: 60.2% rated Good, 38% Fair, 1.9% Poor.
- 108
- Public bridges
- 60.2%
- Good condition
- 1.9%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Brown County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- Top 20%
- lowest Poor share in state
- 1.9%
- Poor-condition share
- 108
- public highway bridges
- 1982
- 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.
Brown County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Brown County ranks #17 of 87 Minnesota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.9%). Brown County, Minnesota contains 108 public highway bridges. Roughly 60.2% are rated “Good,” 38% “Fair,” and 1.9% “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.
Good condition
60.2%
65 of 108 rated 7-9
Fair condition
38%
41 of 108 rated 5-6
Poor condition
1.9%
2 of 108 rated 4 or below
In-state Poor-share rank
#17 of 87
Among Minnesota counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 108 NBI-tracked bridges by lowest applicable component rating.
Good 60.2% (65)
Fair 38% (41)
Poor 1.9% (2)
Brown County's Poor-condition bridges carry 431 vehicle crossings a day
That is 0.6% of the county's reported daily bridge traffic on 1.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 216 crossings a day against 711 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 108 of 108 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
27.8% of Brown County's bridges have passed the 50-year mark
30 of the 108 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 60.2% 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 93.3% of the county's Poor-condition bridge traffic
CSAH 5 over LITTLE COTTONWOOD RIVER, built 1951, carries 402 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 2-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 431 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Brown County's bridges were built
108 bridges with a recorded construction year, grouped by decade
- 1930s 5
1930–1939
5 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 10
1950–1959
10 bridges
- 1960s 7
1960–1969
7 bridges
- 1970s
1970–1979
30 bridges
- 1980s
1980–1989
16 bridges
- 1990s
1990–1999
12 bridges
- 2000s
2000–2009
17 bridges
- 2010s 8
2010–2019
8 bridges
- 2020s 1
2020–2029
1 bridges
What this shows Construction peaked in the 1970s, when 30 of the county's bridges still in the inventory were built, which is 27.8% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1982) matches the Minnesota average (1986).
How Brown County compares with Minnesota's closest counties by inventory size
The 5 Minnesota counties nearest Brown County in number of bridges, with their condition splits. Its 1.9% Poor share is the 2nd-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1989 is 7 years older.
Showing the 5 closest of 86 Minnesota counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Carver County | 115 | 57.4% | 40% | 2.6% | 1995 |
| Washington County | 112 | 42.9% | 52.7% | 4.5% | 1990 |
| Brown County (this page) | 108 | 60.2% | 38% | 1.9% | 1982 |
| Mille Lacs County | 107 | 55.1% | 37.4% | 7.5% | 1986 |
| Lincoln County | 106 | 54.7% | 38.7% | 6.6% | 1981 |
| Sibley County | 102 | 61.8% | 37.3% | 1% | 1994 |
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 Brown 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 Brown County, both outside Minnesota so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MN (108 bridges here).
- Lassen County, CA · 108 bridges
- Pulaski County, IL · 108 bridges
- West Feliciana County, LA · 108 bridges
- Shelby County, MO · 108 bridges
Similar average build year
Nearest mean year-built outside MN (1982 here).
- Oklahoma County, OK · avg 1982 · 1,216 bridges
- Jackson County, MO · avg 1982 · 930 bridges
- Milwaukee County, WI · avg 1982 · 893 bridges
- Champaign County, IL · avg 1982 · 727 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (2)
Read our methodology - how this data is sourced, computed, and verified.
Related
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.