County profile · official public datasets

Mercer County, OH

329 public highway bridges tracked in the FHWA National Bridge Inventory: 41.3% rated Good, 55.9% Fair, 2.7% Poor.

329
Public bridges: 41.3%
Good condition: 2.7%
Poor condition

The verdict

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

Mercer County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 39%
lowest Poor share in state: 2.7%
Poor-condition share: 329
public highway bridges: 1989
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.

Mercer County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Mercer County ranks #34 of 88 Ohio counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.7%). Mercer County, Ohio contains 329 public highway bridges. Roughly 41.3% are rated “Good,” 55.9% “Fair,” and 2.7% “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

329

Public highway bridges in Mercer County

Good condition

41.3%

136 of 329 rated 7-9

Fair condition

55.9%

184 of 329 rated 5-6

Poor condition

2.7%

9 of 329 rated 4 or below

In-state Poor-share rank

#34 of 88

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

Condition distribution

Share of 329 NBI-tracked bridges by lowest applicable component rating.

Good

41.3% (136)

Fair

55.9% (184)

Poor

2.7% (9)

Mercer County's Poor-condition bridges carry 3,363 vehicle crossings a day

That is 1.2% of the county's reported daily bridge traffic on 2.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 374 crossings a day against 1,246 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 329 of 329 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

19.1% of Mercer County's bridges have passed the 50-year mark

63 of the 329 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 41.3% 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 35.5% of the county's Poor-condition bridge traffic

SIEGRIST JUTTE RD over WABASH RIVER, built 1987, carries 1,194 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 9-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,363 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

5
1910s

1
1920s

3
1930s

6
1940s

2
1950s

15
1960s

23
1970s

12
1980s

57
1990s

86
2000s

91
2010s

22
2020s

6

What this shows Construction peaked in the 2000s, when 91 of the county's bridges still in the inventory were built, which is 27.7% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1989, 12 years newer than the Ohio average of 1977.

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

The 5 Ohio counties nearest Mercer County in number of bridges, with their condition splits. Its 2.7% Poor share is the 4th-lowest of these 6. Its average build year of 1989 against a peer-group mean of 1975 is 14 years newer.

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

Bridge inventory size and condition shares for Mercer County and the 5 Ohio counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Tuscarawas County	336	66.7%	31%	2.4%	1981
Warren County	336	58.6%	36%	5.4%	1981
Mercer County (this page)	329	41.3%	55.9%	2.7%	1989
Auglaize County	321	81.9%	17.8%	0.3%	1980
Columbiana County	321	58.9%	38.6%	2.5%	1961
Fairfield County	320	56.6%	38.4%	5%	1973

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

Similar inventory size

Nearest county inventories outside OH (329 bridges here).

Jones County, MS · 329 bridges
Knox County, NE · 329 bridges
Pike County, IL · 330 bridges
Tippecanoe County, IN · 330 bridges

Similar average build year

Nearest mean year-built outside OH (1989 here).

Harris County, TX · avg 1989 · 4,029 bridges
Mecklenburg County, NC · avg 1989 · 746 bridges
Buffalo County, NE · avg 1989 · 459 bridges
Brazos County, TX · avg 1989 · 370 bridges

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

All 329 Good 136 Fair 184 Poor 9

Good-condition bridges (136)

Sort:

Mercer County Bridge Snapshot

Condition distribution

Mercer County's Poor-condition bridges carry 3,363 vehicle crossings a day

19.1% of Mercer County's bridges have passed the 50-year mark

One structure carries 35.5% of the county's Poor-condition bridge traffic

How Mercer 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

Good-condition bridges (136)

TOWNSHIP LINE RD.

SR-219

SR-219

SR-219

SR29

SR29

SR49

SR-197

MERCER ROAD

USR-127

WATKINS RD

C99 (FRYSINGER RD)

T61 TOWNSHIP LINE

Schaadt

CASSELLA MONTZ RD

FT REC MINSTER RD

SCHROEDER ROAD

US. 127

RAUH RD

FOX RD

OREGON ROAD

Wabash Rd

SR-49

TOWNSHIPLINE T61

Philothea

NEPTUNE MENDON RD

HOENIE ROAD

SR-219

WILSON ROAD

C80A CLOVER FOUR

WINKLER ROAD

SR-49

SR-49

SR29

WINKLER RD

WAYNE ST.

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