Total bridges
27
Public highway bridges in Alcona County
County profile · official public datasets
Alcona County, MI
27 public highway bridges tracked in the FHWA National Bridge Inventory: 48.1% rated Good, 33.3% Fair, 18.5% Poor.
- 27
- Public bridges
- 48.1%
- Good condition
- 18.5%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Alcona County pairs a higher-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.
- 74th
- of 83 on Poor share
- 18.5%
- Poor-condition share
- 27
- 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.
Alcona County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Alcona County ranks #74 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 18.5%). Alcona County, Michigan contains 27 public highway bridges. Roughly 48.1% are rated “Good,” 33.3% “Fair,” and 18.5% “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.
Good condition
48.1%
13 of 27 rated 7-9
Fair condition
33.3%
9 of 27 rated 5-6
Poor condition
18.5%
5 of 27 rated 4 or below
In-state Poor-share rank
#74 of 83
Among Michigan counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 27 NBI-tracked bridges by lowest applicable component rating.
Good 48.1% (13)
Fair 33.3% (9)
Poor 18.5% (5)
Alcona County's Poor-condition bridges carry 3,338 vehicle crossings a day
That is 14.6% of the county's reported daily bridge traffic on 18.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 668 crossings a day against 272 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 27 of 27 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
29.6% of Alcona County's bridges have passed the 50-year mark
8 of the 27 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 48.1% 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 51.8% of the county's Poor-condition bridge traffic
HURBERT ROAD over THUNDER BAY RIVER, built 1955, carries 1,730 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 5-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 3,338 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Alcona County's bridges were built
27 bridges with a recorded construction year, grouped by decade
- 1930s 3
1930–1939
3 bridges
- 1950s
1950–1959
4 bridges
- 1970s 2
1970–1979
2 bridges
- 1980s 3
1980–1989
3 bridges
- 1990s
1990–1999
9 bridges
- 2000s 3
2000–2009
3 bridges
- 2010s 3
2010–2019
3 bridges
What this shows Construction peaked in the 1990s, when 9 of the county's bridges still in the inventory were built, which is 33.3% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year is 1982, 6 years newer than the Michigan average of 1976.
How Alcona County compares with Michigan's closest counties by inventory size
The 5 Michigan counties nearest Alcona County in number of bridges, with their condition splits. Its 18.5% Poor share is the 5th-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1972 is 10 years newer.
Showing the 5 closest of 82 Michigan counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Ogemaw County | 31 | 22.6% | 74.2% | 3.2% | 1969 |
| Lake County | 30 | 43.3% | 40% | 16.7% | 1967 |
| Luce County | 28 | 39.3% | 42.9% | 17.9% | 1981 |
| Alcona County (this page) | 27 | 48.1% | 33.3% | 18.5% | 1982 |
| Benzie County | 25 | 28% | 40% | 32% | 1969 |
| Otsego County | 25 | 16% | 76% | 8% | 1976 |
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 Alcona 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 Alcona County, both outside Michigan so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MI (27 bridges here).
- Denali County, AK · 27 bridges
- Phillips County, CO · 27 bridges
- Teller County, CO · 27 bridges
- Baker County, GA · 27 bridges
Similar average build year
Nearest mean year-built outside MI (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 (5)
HURBERT ROAD
PoorOver: THUNDER BAY RIVER
1 MI N 6.5 MI W OF SPRUCE, Alcona, MI
Built 1955 Load: 10.4 t ADT: 1,730
MCCONNEL ROAD
PoorOver: EAST BRANCH PINE RIVER
0.9 MILES SOUTH OF M 72, Alcona, MI
Built 1935 Load: 10.7 t ADT: 159
CRUZEN ROAD
PoorOver: SO BRANCH OF PINE RIVER
2.0 MI W 1.2 MI S MIKADO, Alcona, MI
Built 1984 Load: 15.6 t ADT: 339
HUBBARD LAKE ROAD
PoorOver: SUCKER CREEK
8 MI N OF M-72, Alcona, MI
Built 1936 Load: 28.1 t ADT: 830
LAKESHORE DRIVE
PoorOver: BLACK RIVER
VILLAGE OF BLACK RIVER, Alcona, MI
Built 1984 Load: 30.5 t ADT: 280
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.