County profile · official public datasets

Gladwin County, MI

63 public highway bridges tracked in the FHWA National Bridge Inventory: 47.6% rated Good, 46% Fair, 6.3% Poor.

63
Public bridges: 47.6%
Good condition: 6.3%
Poor condition

The verdict

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

Gladwin County pairs a top-quartile lowest Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 25%
lowest Poor share in state: 6.3%
Poor-condition share: 63
public highway bridges: 1981
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.

Gladwin County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Gladwin County ranks #21 of 83 Michigan counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.3%). Gladwin County, Michigan contains 63 public highway bridges. Roughly 47.6% are rated “Good,” 46% “Fair,” and 6.3% “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

Public highway bridges in Gladwin County

Good condition

47.6%

30 of 63 rated 7-9

Fair condition

46%

29 of 63 rated 5-6

Poor condition

6.3%

4 of 63 rated 4 or below

In-state Poor-share rank

#21 of 83

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

Condition distribution

Share of 63 NBI-tracked bridges by lowest applicable component rating.

Good

47.6% (30)

Fair

46% (29)

Poor

6.3% (4)

Gladwin County's Poor-condition bridges carry 9,716 vehicle crossings a day

That is 12.3% of the county's reported daily bridge traffic on 6.3% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 2,429 crossings a day against 797 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 63 of 63 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

28.6% of Gladwin County's bridges have passed the 50-year mark

18 of the 63 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 47.6% 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 62.8% of the county's Poor-condition bridge traffic

M-18 over TOBACCO RIVER, built 1939, carries 6,100 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 4-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 9,716 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

3
1930s

2
1950s

5
1960s

3
1970s

11
1980s

13
1990s

9
2000s

8
2010s

4
2020s

3

What this shows Construction peaked in the 1980s, when 13 of the county's bridges still in the inventory were built, which is 20.6% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1981, 5 years newer than the Michigan average of 1976.

How Gladwin County compares with Michigan's closest counties by inventory size

The 5 Michigan counties nearest Gladwin County in number of bridges, with their condition splits. Its 6.3% Poor share is the 2nd-lowest of these 6. Its average build year of 1981 against a peer-group mean of 1976 is 5 years newer.

Showing the 5 closest of 82 Michigan counties eligible for comparison.

Bridge inventory size and condition shares for Gladwin County and the 5 Michigan counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Mason County	66	39.4%	53%	7.6%	1977
Newaygo County	65	43.1%	46.2%	10.8%	1979
Ontonagon County	64	37.5%	46.9%	15.6%	1970
Wexford County	64	26.6%	67.2%	6.3%	1986
Mackinac County	63	25.4%	55.6%	19%	1966
Gladwin County (this page)	63	47.6%	46%	6.3%	1981

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

Similar inventory size

Nearest county inventories outside MI (63 bridges here).

Highlands County, FL · 63 bridges
Chattahoochee County, GA · 63 bridges
Red River County, LA · 63 bridges
Lincoln County, ME · 63 bridges

Similar average build year

Nearest mean year-built outside MI (1981 here).

Franklin County, OH · avg 1981 · 922 bridges
Greenville County, SC · avg 1981 · 635 bridges
Montgomery County, OH · avg 1981 · 632 bridges
McLean County, IL · avg 1981 · 624 bridges

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

All 63 Good 30 Fair 29 Poor 4

All bridges (63)

Sort:

Gladwin County Bridge Snapshot

Condition distribution

Gladwin County's Poor-condition bridges carry 9,716 vehicle crossings a day

28.6% of Gladwin County's bridges have passed the 50-year mark

One structure carries 62.8% of the county's Poor-condition bridge traffic

How Gladwin County compares with Michigan's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

All bridges (63)

M-18

SHELL RD

POLEGATE RD

BARD RD

PINCONNING RD

KLENDER RD

PORTER STREET

BENSCH RD

HERNER RD

MCCULLOUGH RD

ESTEY RD

BEAVERTON RD

BARD RD

CALHOUN ROAD

GLIDDEN RD

DUTCHER RD

M-61

M-61

M-30

CALHOUN RD

M-30

HOWARD RD

M-18

M-30

M-18

GROUT RD

BARD RD

M-30

KNOX RD

BARD ROAD

HOCKADAY RD

SWINSON NEUMAN RD

RHODES RD

SHEARER RD

SCHMIDT RD

YOUNGS RD

NICKLESS RD

NETTLETON RD

GRASS LAKE RD

DASSEY RD

LANG RD

RITCHIE RD

M-30

BADGER RD

MCCULLOCH RD

M-18

SECORD DAM ROAD

DALE ROAD

HOWARD RD

EAGLESON RD

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