County profile · official public datasets

Logan County, OH

281 public highway bridges tracked in the FHWA National Bridge Inventory: 78.3% rated Good, 20.6% Fair, 1.1% Poor.

281
Public bridges: 78.3%
Good condition: 1.1%
Poor condition

The verdict

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

Logan County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 11%
lowest Poor share in state: 1.1%
Poor-condition share: 281
public highway bridges: 1979
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.

Logan County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Logan County ranks #10 of 88 Ohio counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 1.1%). Logan County, Ohio contains 281 public highway bridges. Roughly 78.3% are rated “Good,” 20.6% “Fair,” and 1.1% “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

281

Public highway bridges in Logan County

Good condition

78.3%

220 of 281 rated 7-9

Fair condition

20.6%

58 of 281 rated 5-6

Poor condition

1.1%

3 of 281 rated 4 or below

In-state Poor-share rank

#10 of 88

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

Condition distribution

Share of 281 NBI-tracked bridges by lowest applicable component rating.

Good

78.3% (220)

Fair

20.6% (58)

Poor

1.1% (3)

Logan County's Poor-condition bridges carry 1,172 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 1.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 391 crossings a day against 1,608 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 281 of 281 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

39.1% of Logan County's bridges have passed the 50-year mark

110 of the 281 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 78.3% 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 69.6% of the county's Poor-condition bridge traffic

CR 21B over MIAMI RIVER, built 1882, carries 816 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 3-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,172 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

2
1900s

14
1910s

4
1920s

1
1930s

7
1940s

5
1950s

8
1960s

59
1970s

22
1980s

20
1990s

60
2000s

60
2010s

15
2020s

4

What this shows Construction peaked in the 1990s, when 60 of the county's bridges still in the inventory were built, which is 21.4% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1979) matches the Ohio average (1977).

How Logan County compares with Ohio's closest counties by inventory size

The 5 Ohio counties nearest Logan County in number of bridges, with their condition splits. Its 1.1% Poor share is the 1st-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1982 is in line with the group.

Showing the 5 closest of 87 Ohio counties eligible for comparison.

Bridge inventory size and condition shares for Logan County and the 5 Ohio counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Ashland County	283	65%	32.5%	2.5%	1980
Logan County (this page)	281	78.3%	20.6%	1.1%	1979
Shelby County	277	74%	23.5%	2.5%	1989
Hardin County	276	64.1%	28.6%	7.2%	1979
Seneca County	275	72.7%	25.8%	1.5%	1983
Knox County	274	54.4%	40.1%	5.5%	1980

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

Similar inventory size

Nearest county inventories outside OH (281 bridges here).

Smith County, KS · 281 bridges
Daviess County, KY · 282 bridges
Acadia County, LA · 282 bridges
New Madrid County, MO · 282 bridges

Similar average build year

Nearest mean year-built outside OH (1979 here).

Pima County, AZ · avg 1979 · 1,150 bridges
Jefferson County, KY · avg 1979 · 662 bridges
Spartanburg County, SC · avg 1979 · 638 bridges
McPherson County, KS · avg 1979 · 586 bridges

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

All 281 Good 220 Fair 58 Poor 3

All bridges (281)

Sort:

Logan County Bridge Snapshot

Condition distribution

Logan County's Poor-condition bridges carry 1,172 vehicle crossings a day

39.1% of Logan County's bridges have passed the 50-year mark

One structure carries 69.6% of the county's Poor-condition bridge traffic

How Logan County compares with Ohio'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 (281)

SR 117

SR 235

SR 235

SR 245

SR 273

SR 274

SR 274

SR-292

SR-292

SR-292

SR-347

SR-366

SR-368

SR-508

SR-540

SR-540

SR-638

SR-638

SR 638

SR-708

CR 5

TR 51

CR 10

C.R. 10

C.R. 10

CR20

CR 25

CR 26

CR 54

CR 59

CR91

CR 121

COUNTY ROAD 152

COUNTY ROAD 154

TR 178

TR 256

COUNTY ROAD 8

CR 64

TOWNSHIP ROAD 295

LOG C124 UNI C361A

CR 277

CR 296

TOWNSHIP ROAD 97

USR 33

USR 33

USR 68

SR 235

SR 274

CR 4

CR 12

Related