County profile · official public datasets

Marion County, OH

229 public highway bridges tracked in the FHWA National Bridge Inventory: 63.8% rated Good, 34.1% Fair, 2.2% Poor.

229
Public bridges: 63.8%
Good condition: 2.2%
Poor condition

The verdict

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

Marion County posts a better-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 26%
lowest Poor share in state: 2.2%
Poor-condition share: 229
public highway bridges: 1975
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.

Marion County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Marion County ranks #23 of 88 Ohio counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.2%). Marion County, Ohio contains 229 public highway bridges. Roughly 63.8% are rated “Good,” 34.1% “Fair,” and 2.2% “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

229

Public highway bridges in Marion County

Good condition

63.8%

146 of 229 rated 7-9

Fair condition

34.1%

78 of 229 rated 5-6

Poor condition

2.2%

5 of 229 rated 4 or below

In-state Poor-share rank

#23 of 88

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

Condition distribution

Share of 229 NBI-tracked bridges by lowest applicable component rating.

Good

63.8% (146)

Fair

34.1% (78)

Poor

2.2% (5)

Marion County's Poor-condition bridges carry 1,904 vehicle crossings a day

That is 0.4% of the county's reported daily bridge traffic on 2.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 381 crossings a day against 2,519 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 229 of 229 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

48% of Marion County's bridges have passed the 50-year mark

110 of the 229 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 63.8% 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 36.7% of the county's Poor-condition bridge traffic

SR 37 over SCIOTO RIVER, built 1950, carries 699 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 1,904 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

15
1930s

2
1940s

5
1950s

16
1960s

63
1970s

19
1980s

27
1990s

44
2000s

23
2010s

13
2020s

2

What this shows Construction peaked in the 1960s, when 63 of the county's bridges still in the inventory were built, which is 27.5% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1975) matches the Ohio average (1977).

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

The 5 Ohio counties nearest Marion County in number of bridges, with their condition splits. Its 2.2% Poor share is the 3rd-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1973 is in line with the group.

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

Bridge inventory size and condition shares for Marion County and the 5 Ohio counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Wyandot County	236	71.2%	27.1%	1.7%	1984
Marion County (this page)	229	63.8%	34.1%	2.2%	1975
Jefferson County	226	44.2%	47.3%	8.4%	1966
Erie County	225	66.7%	32.9%	0.4%	1977
Pickaway County	224	62.9%	34.8%	2.2%	1964
Brown County	223	62.8%	34.1%	3.1%	1974

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

Similar inventory size

Nearest county inventories outside OH (229 bridges here).

Walton County, FL · 229 bridges
Aroostook County, ME · 229 bridges
Stearns County, MN · 229 bridges
Itawamba County, MS · 229 bridges

Similar average build year

Nearest mean year-built outside OH (1975 here).

San Bernardino County, CA · avg 1975 · 1,422 bridges
Lane County, OR · avg 1975 · 1,010 bridges
Fulton County, GA · avg 1975 · 775 bridges
Westmoreland County, PA · avg 1975 · 620 bridges

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

All 229 Good 146 Fair 78 Poor 5

Fair-condition bridges (78)

Sort:

Marion County Bridge Snapshot

Condition distribution

Marion County's Poor-condition bridges carry 1,904 vehicle crossings a day

48% of Marion County's bridges have passed the 50-year mark

One structure carries 36.7% of the county's Poor-condition bridge traffic

How Marion 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

Fair-condition bridges (78)

TOWNSHIP ROAD 40

COUNTY ROAD 142

TOWNSHIP ROAD 28

COUNTY ROAD 197E

COUNTY ROAD 140

SR 529

SR 203

COUNTY ROAD 30

TOWNSHIP ROAD 31

TOWNSHIP ROAD 142

SR 529

SR 100

SR 309

SR 37

SR 95

SR 98

SR 739

SR 746

SR 746

COUNTY ROAD 73

CR 169

SR 95

COUNTY ROAD 67

TOWNSHIP ROAD 123

COUNTY ROAD 163

SR 309

SR 309

SR 203

SR 37

SR 4

US 23

US 23

SR 423

COUNTY ROAD 002D

COUNTY ROAD 26

COUNTY ROAD 26

TOWNSHIP ROAD 51

TOWNSHIP ROAD 55

COUNTY ROAD 67

TOWNSHIP ROAD 84

COUNTY ROAD 104

COUNTY ROAD 67

COUNTY ROAD 106

KELLOGG PARKWAY

TOWNSHIP ROAD 27

SR 309

SR 309

SR 95

SR 95

SR 4D

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