County profile · official public datasets

Knox County, OH

274 public highway bridges tracked in the FHWA National Bridge Inventory: 54.4% rated Good, 40.1% Fair, 5.5% Poor.

274
Public bridges: 54.4%
Good condition: 5.5%
Poor condition

The verdict

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

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

55th
of 88 on Poor share: 5.5%
Poor-condition share: 274
public highway bridges: 1980
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.

Knox County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Knox County ranks #55 of 88 Ohio counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 5.5%). Knox County, Ohio contains 274 public highway bridges. Roughly 54.4% are rated “Good,” 40.1% “Fair,” and 5.5% “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.

Total bridges

274

Public highway bridges in Knox County

Good condition

54.4%

149 of 274 rated 7-9

Fair condition

40.1%

110 of 274 rated 5-6

Poor condition

5.5%

15 of 274 rated 4 or below

In-state Poor-share rank

#55 of 88

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

Condition distribution

Share of 274 NBI-tracked bridges by lowest applicable component rating.

Good

54.4% (149)

Fair

40.1% (110)

Poor

5.5% (15)

Knox County's Poor-condition bridges carry 5,343 vehicle crossings a day

That is 1.3% of the county's reported daily bridge traffic on 5.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 356 crossings a day against 1,974 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 274 of 274 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

32.5% of Knox County's bridges have passed the 50-year mark

89 of the 274 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 54.4% 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 23.9% of the county's Poor-condition bridge traffic

HOWARD DANVILLE over LITTLE JELLOWAY CREEK, built 1915, carries 1,277 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 15-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,343 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

2
1900s

19
1910s

3
1920s

6
1930s

18
1940s

5
1950s

14
1960s

12
1970s

17
1980s

23
1990s

62
2000s

45
2010s

40
2020s

8

What this shows Construction peaked in the 1990s, when 62 of the county's bridges still in the inventory were built, which is 22.6% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1980) matches the Ohio average (1977).

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

The 5 Ohio counties nearest Knox County in number of bridges, with their condition splits. Its 5.5% Poor share is the 5th-lowest of these 6. Its average build year of 1980 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 Knox County and the 5 Ohio counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Logan County	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 (this page)	274	54.4%	40.1%	5.5%	1980
Delaware County	268	70.5%	27.2%	2.2%	1982

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

Similar inventory size

Nearest county inventories outside OH (274 bridges here).

Cass County, NE · 274 bridges
Wayne County, TN · 274 bridges
Walker County, AL · 275 bridges
Ellis County, KS · 275 bridges

Similar average build year

Nearest mean year-built outside OH (1980 here).

Tulsa County, OK · avg 1980 · 1,135 bridges
Miami-Dade County, FL · avg 1980 · 1,057 bridges
Pulaski County, AR · avg 1980 · 721 bridges
McLennan County, TX · avg 1980 · 714 bridges

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

All 274 Good 149 Fair 110 Poor 15

Good-condition bridges (149)

Sort:

Knox County Bridge Snapshot

Condition distribution

Knox County's Poor-condition bridges carry 5,343 vehicle crossings a day

32.5% of Knox County's bridges have passed the 50-year mark

One structure carries 23.9% of the county's Poor-condition bridge traffic

How Knox 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 (149)

LWR FRED-AMITY RD

MONTGOMERY RD

CO 54 BIG RUN

GRANNY CREEK ROAD

GREEN VALLEY

ORANGE HILL RD

BOWMAN RD

KILLDUFF ROAD

PERRY ROAD

STULL

CAREY LANE

ESTO ROAD

GARBER ROAD

LARIMORE ROAD

GRAHAM ROAD

WARD RD

BECKLEY ROAD

TR 140

EARNEST ROAD

SR 541

LOWER GAMBIER RD

MOUNT VERNON AVE.

SR 13

US 36

APPLE VALLEY DR

Magers Rd

BEAVER RD

COLUMBUS ROAD

Parrot St

DUNHAM RD

STAATS ROAD

SR 514

SR 661

SR 229

GLEN RD

SR 586

SR 3

COFFING RD

SR 205

SR 13

SR 661

COUNTY ROAD 25

COUNTY ROAD 17

BEAR RUN RD

ORANGE HILL ROAD

Caves Road

SR 657

US 36 & SR 3

OLD MANSFIELD

HOPEWELL

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