County profile · official public datasets

Miami County, OH

315 public highway bridges tracked in the FHWA National Bridge Inventory: 72.1% rated Good, 21% Fair, 7% Poor.

315
Public bridges
72.1%
Good condition
7%
Poor condition

The verdict

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

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

65th
of 88 on Poor share
7%
Poor-condition share
315
public highway bridges
1983
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.

Miami County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Miami County ranks #65 of 88 Ohio counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7%). Miami County, Ohio contains 315 public highway bridges. Roughly 72.1% are rated “Good,” 21% “Fair,” and 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

315

Public highway bridges in Miami County

Good condition

72.1%

227 of 315 rated 7-9

Fair condition

21%

66 of 315 rated 5-6

Poor condition

7%

22 of 315 rated 4 or below

In-state Poor-share rank

#65 of 88

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

Condition distribution

Share of 315 NBI-tracked bridges by lowest applicable component rating.

Good
72.1% (227)
Fair
21% (66)
Poor
7% (22)

Miami County's Poor-condition bridges carry 22,399 vehicle crossings a day

That is 1.2% of the county's reported daily bridge traffic on 7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,018 crossings a day against 6,968 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 315 of 315 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

41.9% of Miami County's bridges have passed the 50-year mark

132 of the 315 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 72.1% 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 14.4% of the county's Poor-condition bridge traffic

KESSLER-FREDERICK over STONER DITCH, built 1954, carries 3,227 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 22-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 22,399 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Miami County's bridges were built

315 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1960s, when 60 of the county's bridges still in the inventory were built, which is 19% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1983, 6 years newer than the Ohio average of 1977.

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Ohio counties nearest Miami County in number of bridges, with their condition splits. Its 7% Poor share is the 4th-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1978 is 5 years newer.

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

Bridge inventory size and condition shares for Miami County and the 5 Ohio counties closest to it in inventory size
County Bridges Poor
Fairfield County 320 5%
Clermont County 319 8.5%
Van Wert County 317 0%
Miami County (this page) 315 7%
Huron County 311 8%
Belmont County 310 5.2%

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

Similar inventory size

Nearest county inventories outside OH (315 bridges here).

Similar average build year

Nearest mean year-built outside OH (1983 here).

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

All 315 Good 227 Fair 66 Poor 22

All bridges (315)

WIDENER

Fair

Over: INDIAN CREEK

0.93 E OF SR201, Miami, OH

Built 1968 Load: 33.4 t ADT: 80

DAYTON-BRANDT

Fair

Over: STAFFORD DITCH

0.08 N OF CR8, Miami, OH

Built 1973 Load: 34.7 t ADT: 364

STUDEBAKER

Fair

Over: BRANCH HONEY CREEK

0.27 E OF SR201, Miami, OH

Built 1973 Load: 34.7 t ADT: 266

SR-66

Fair

Over: HYDRAULIC SPILLWAY

1.8MI.N. OF JCT. USR-36, Miami, OH

Built 1960 Load: 35.0 t ADT: 4,672

SR-41

Fair

Over: PLEASANT RUN CREEK

2.18MI.W. OF JCT. SR-201, Miami, OH

Built 1977 Load: 35.6 t ADT: 2,208

SR-55

Fair

Over: LOST CREEK

.83MI.W. OF JCT. SR-589, Miami, OH

Built 1929 Load: 36.0 t ADT: 2,960

FENNER

Fair

Over: WEST BRANCH PETERS CREEK

0.55 E OF CR132, Miami, OH

Built 1970 Load: 36.3 t ADT: 2,301

RAMP I-75

Fair

Over: RAMP C OVER PETERS CREEK

RAMP SB I-75 TO SR-55, Miami, OH

Built 1968 Load: 36.6 t ADT: 23,630

FREDERICK-GARLAND

Fair

Over: STILLWATER RIVER PJM

0.84 E OF SR48, Miami, OH

Built 1977 Load: 38.9 t ADT: 1,603

LYTLE

Fair

Over: BEEDLE DITCH

0.07 S OF CR33, Miami, OH

Built 1955 Load: 38.9 t ADT: 2,227

SR 41

Fair

Over: GREAT MIAMI RIVER

.58M W.OF SR202, Miami, OH

Built 1960 Load: 39.2 t ADT: 6,525

SR-571

Fair

Over: GREAT MIAMI RIVER

.43 MI. W. OF JCT. SR-202, Miami, OH

Built 1984 Load: 48.6 t ADT: 7,460

NORTH ADAMS STREET

Fair

Over: CHESSIE SYSTEM RAILROAD

N ADAMS ST RR OVERPASS, Miami, OH

Built 1974 Load: 48.6 t ADT: 5,000

LOY

Fair

Over: SPRING CREEK

0.56 E OF CR184, Miami, OH

Built 1964 Load: 58.6 t ADT: 867

RANGE LINE

Fair

Over: GREENVILLE CREEK

0.03 S OF CR81, Miami, OH

Built 1967 Load: 61.6 t ADT: 1,030

CR 33 Eldean

Fair

Over: BEEDLE DITCH

0.42 MI E. OF CR 36, Miami, OH

Built 1955 Load: 77.8 t ADT: 5,010

CR81 COV-GETTYS RD

Good

Over: GREENVILLE CREEK

0.01 MI W. OF TR85, Miami, OH

Built 2005 Load: 0.0 t ADT: 427

C86 Bradfrd-Bloomr

Good

Over: SPROAT DITCH

0.57 MI S OF CR28, Miami, OH

Built 2000 Load: 0.0 t ADT: 637

CR 241

Good

Over: BRANCH MUD CREEK

0.63 N. OF CR177, Miami, OH

Built 2001 Load: 0.0 t ADT: 1,051

KARNS

Good

Over: MILL CREEK

0.05 S OF CR12, Miami, OH

Built 1991 Load: 19.4 t ADT: 797

SPRINGCREEK

Good

Over: RUSH CREEK

0.89 N OF CR197, Miami, OH

Built 1959 Load: 19.4 t ADT: 351

SR-201

Good

Over: INDIAN CREEK

1.78MI.N. OF JCT. SR-571, Miami, OH

Built 1960 Load: 21.4 t ADT: 1,661

SR-201

Good

Over: DRY CREEK

.83MI.S. OF JCT. SR-41, Miami, OH

Built 1960 Load: 22.0 t ADT: 1,661

USR-36

Good

Over: GREAT MIAMI RIVER

.44MI.W. OF JCT. IR-75, Miami, OH

Built 1965 Load: 22.7 t ADT: 13,325

SR589

Good

Over: LITTLE LOST CREEK

.08 MI. N. OF JCT. SR55, Miami, OH

Built 1967 Load: 22.7 t ADT: 1,662

SR589

Good

Over: BRANCH LOST CREEK

1.76 MI. N.OF JCT. SR55, Miami, OH

Built 1966 Load: 22.7 t ADT: 1,662

DITMER

Good

Over: LUDLOW CREEK

1.10 N OF CR45, Miami, OH

Built 1971 Load: 22.7 t ADT: 385

IR-75

Good

Over: GREAT MIAMI RIVER

3.44MI.S. OF JCT. USR-36, Miami, OH

Built 1958 Load: 24.3 t ADT: 23,381

SR-66

Good

Over: SWIFT RUN

2.04 MI. S. OF SHELBY CO., Miami, OH

Built 1960 Load: 24.6 t ADT: 4,672

SR-202

Good

Over: LOST CREEK

1.91MI.S. OF JCT. SR-41, Miami, OH

Built 1955 Load: 24.6 t ADT: 3,264

SR-48

Good

Over: STILLWATER RIVER

1.68MI.S. OF JCT. SR-718, Miami, OH

Built 1961 Load: 24.9 t ADT: 2,400

SR-55

Good

Over: WEST BR.OF PETERS CREEK

.9MI.W. OF JCT. IR-75, Miami, OH

Built 1968 Load: 25.9 t ADT: 6,881

SHOOP ROAD

Good

Over: IR 75

1.01MI.N.OF MONTGOMERY CO, Miami, OH

Built 1962 Load: 25.9 t ADT: 1,000

EVANSTON ROAD

Good

Over: IR 75

1.11MI.S. OF JCT. SR-571, Miami, OH

Built 1962 Load: 25.9 t ADT: 2,561

SR-185

Good

Over: TROTTERS CREEK

.15MI.W. OF JCT. SR-48, Miami, OH

Built 1963 Load: 25.9 t ADT: 2,844

SR-201

Good

Over: HONEY CREEK

.57MI. N O F JCT. SR-571, Miami, OH

Built 1963 Load: 25.9 t ADT: 1,661

SR-721

Good

Over: HOG RUN

.61MI.S. OF JCT. SR-571, Miami, OH

Built 1968 Load: 25.9 t ADT: 1,189

LOSTCREEK-SHELBY

Good

Over: EAST BRANCH LOST CREEK

0.91 N OF CR17, Miami, OH

Built 1984 Load: 25.9 t ADT: 164

SR-721

Good

Over: LUDLOW CREEK

1.9MI.S. OF JCT. SR-55, Miami, OH

Built 1961 Load: 27.2 t ADT: 642

SR-48

Good

Over: TROTTERS CREEK

1.37MI.N. OF JCT. USR-36, Miami, OH

Built 1963 Load: 28.2 t ADT: 4,362

USR-36

Good

Over: IR 75

JCT. IR-75, Miami, OH

Built 1958 Load: 29.2 t ADT: 8,052

IR-75

Good

Over: TR 42 GINGHAMSBURG ROAD

.43MI.N. OF MONTGOMERY CO, Miami, OH

Built 1956 Load: 29.2 t ADT: 34,748

IR-75

Good

Over: TR 42 GINGHAMSBURG ROAD

.43MI.N. OF MONTGOMERY CO, Miami, OH

Built 1956 Load: 29.2 t ADT: 34,748

I-75 RAMP

Good

Over: PETERS CREEK

RAMP SR-55 TO NB 75, Miami, OH

Built 2002 Load: 29.2 t ADT: 4,042

IR-75

Good

Over: ABANDONED RR

3.19MI.N. OF JCT. SR-41, Miami, OH

Built 1957 Load: 29.2 t ADT: 23,381

IR-75

Good

Over: B & O RR

2.15MI. S. OF JCT. USR-36, Miami, OH

Built 1958 Load: 29.2 t ADT: 22,249

IR-75

Good

Over: B & O RR

2.15MI.S. OF JCT. USR-36, Miami, OH

Built 1958 Load: 29.2 t ADT: 22,249

IR-75

Good

Over: PATRIZIO PLACE

.52MI.S. OF JCT. USR-36, Miami, OH

Built 2013 Load: 29.2 t ADT: 24,443

SR589

Good

Over: BRANCH LOST CREEK

2.3 MI. S.OF JCT.USR36, Miami, OH

Built 1966 Load: 29.2 t ADT: 1,662

SR-718

Good

Over: STILLWATER RIVER

1.22MI.W. OF JCT. SR-48, Miami, OH

Built 1964 Load: 29.2 t ADT: 1,814

Read our methodology - how this data is sourced, computed, and verified.

Related

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.