County profile · official public datasets

Miami County, KS

326 public highway bridges tracked in the FHWA National Bridge Inventory: 64.7% rated Good, 31.9% Fair, 3.4% Poor.

326
Public bridges
64.7%
Good condition
3.4%
Poor condition

The verdict

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

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

Top 41%
lowest Poor share in state
3.4%
Poor-condition share
326
public highway bridges
1974
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 #43 of 104 Kansas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.4%). Miami County, Kansas contains 326 public highway bridges. Roughly 64.7% are rated “Good,” 31.9% “Fair,” and 3.4% “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

326

Public highway bridges in Miami County

Good condition

64.7%

211 of 326 rated 7-9

Fair condition

31.9%

104 of 326 rated 5-6

Poor condition

3.4%

11 of 326 rated 4 or below

In-state Poor-share rank

#43 of 104

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

Condition distribution

Share of 326 NBI-tracked bridges by lowest applicable component rating.

Good
64.7% (211)
Fair
31.9% (104)
Poor
3.4% (11)

Miami County's Poor-condition bridges carry 1,161 vehicle crossings a day

That is 0.2% of the county's reported daily bridge traffic on 3.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 106 crossings a day against 2,084 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 326 of 326 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

41.4% of Miami County's bridges have passed the 50-year mark

135 of the 326 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 64.7% 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 56.4% of the county's Poor-condition bridge traffic

Woodland Road over TRIB. TO SWEETWATER CRK, built 2005, carries 655 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,161 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

326 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 2000s, when 63 of the county's bridges still in the inventory were built, which is 19.3% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year (1974) matches the Kansas average (1972).

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

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

The 5 Kansas counties nearest Miami County in number of bridges, with their condition splits. Its 3.4% Poor share is the 1st-lowest of these 6. Its average build year of 1974 against a peer-group mean of 1968 is 6 years newer.

Showing the 5 closest of 103 Kansas counties eligible for comparison.

Bridge inventory size and condition shares for Miami County and the 5 Kansas counties closest to it in inventory size
County Bridges Poor
Washington County 335 3.9%
Franklin County 332 4.2%
Montgomery County 326 5.5%
Miami County (this page) 326 3.4%
Marion County 324 9.6%
Cherokee County 317 4.4%

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 Kansas so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside KS (326 bridges here).

Similar average build year

Nearest mean year-built outside KS (1974 here).

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

All 326 Good 211 Fair 104 Poor 11

All bridges (326)

US-169 HIGHWAY SB

Good

Over: POTTAWATOMIE CREEK

1.66 MI N JCT K-7 HIGHWAY, Miami, KS

Built 2005 Load: 51.7 t ADT: 3,345

US-169 HIGHWAY NB

Good

Over: BNSF RR; LOCAL ROAD

4.18 MI N K-279 HIGHWAY, Miami, KS

Built 2005 Load: 51.7 t ADT: 6,250

Indianapolis Road

Good

Over: TRIB. MARAIS DES CYGNES

7.2W 0.5S OF PAOLA, Miami, KS

Built 1966 Load: 53.3 t ADT: 38

351st ST

Good

Over: ELM CREEK

9.0S 1.5E OF LOUISBURG, Miami, KS

Built 2006 Load: 53.4 t ADT: 20

Mission Belleview

Good

Over: PONEY CREEK

2.0N 2.0E of Louisburg, Miami, KS

Built 2003 Load: 55.2 t ADT: 151

RS1705 / 311th St.

Good

Over: US69 HWY

4.06 MI S OF K-68, Miami, KS

Built 1979 Load: 56.3 t ADT: 1,061

223rd Street

Good

Over: LITTLE BULL CREEK

1.0S 1.9W OF SPRING HILL, Miami, KS

Built 2017 Load: 61.1 t ADT: 1,302

335th ST

Good

Over: MIDDLE CREEK

7.0S 1.2W OF LOUISBURG, Miami, KS

Built 1990 Load: 61.7 t ADT: 230

US-169 HIGHWAY NB

Good

Over: UP RAILROAD

.77 MI N K-68 HIGHWAY, Miami, KS

Built 2003 Load: 63.5 t ADT: 6,600

US-169/K-7 HIGHWAY

Good

Over: BNSF RAILROAD

4.75 MI N K-68 HIGHWAY, Miami, KS

Built 2003 Load: 63.5 t ADT: 6,900

287th Street

Good

Over: BIG BULL CREEK

2.4N 0.2W OF PAOLA, Miami, KS

Built 2000 Load: 66.7 t ADT: 548

K-68 HWY

Good

Over: COLDWATER CREEK DRAINAGE

3.82 MI E OF US-69, Miami, KS

Built 1991 Load: 77.1 t ADT: 2,560

K-68 HWY

Good

Over: COLDWATER CREEK

4.09 MI E OF US-69, Miami, KS

Built 1991 Load: 83.5 t ADT: 2,560

US 169 HWY

Good

Over: MARAIS DES CYGNES R DRN

0.71 MI N OF K-279, Miami, KS

Built 1973 Load: 89.8 t ADT: 5,150

Crescent Hill Road

Good

Over: MOUND CREEK

1.3S 1.0W of Beagle, Miami, KS

Built 2015 Load: 90.6 t ADT: 85

239th Street

Poor

Over: TRIB. TO ROCK CREEK

6.9W 8.0N OF PAOLA, Miami, KS

Built 1915 Load: 5.4 t ADT: 48

399th ST

Poor

Over: LA CYGNE LAKE

4.4E 4.0S NEW LANCASTER, Miami, KS

Built 1962 Load: 6.9 t ADT: 95

351st Street

Poor

Over: MIDDLE CREEK

9.0S 3.6W OF LOUISBURG, Miami, KS

Built 1920 Load: 9.0 t ADT: 35

New Lancaster Rd

Poor

Over: TRIB. TO MIDDLE CREEK

8.0S 2.9W OF LOUISBURG, Miami, KS

Built 1920 Load: 10.0 t ADT: 94

323rd Street

Poor

Over: TRIB. MARAIS DES CYGNES

2.5S 8.7W OF PAOLA, Miami, KS

Built 1930 Load: 13.6 t ADT: 14

399th Street

Poor

Over: TRIB. TO MIDDLE CREEK

1.0S 0.8W OF BEAGLE, Miami, KS

Built 1935 Load: 13.6 t ADT: 23

311th Street

Poor

Over: TRIB. MARAIS DES CYGNES

1.0S 7.7W OF PAOLA, Miami, KS

Built 1918 Load: 15.4 t ADT: 30

Woodland Road

Poor

Over: TRIB. TO SWEETWATER CRK

0.1E OF SPRING HILL, Miami, KS

Built 2005 Load: 17.4 t ADT: 655

319th Street

Poor

Over: TRIB. MARAIS DES CYGNES

1.7S 7.2W OF PAOLA, Miami, KS

Built 1993 Load: 18.1 t ADT: 17

255th Street

Poor

Over: STREAM

3.0N 2.8W OF LOUISBURG, Miami, KS

Built 1965 Load: 20.0 t ADT: 102

267th Street

Poor

Over: TRIB. TO TEN MILE CREEK

1.0S 0.9E OF HILLSDALE, Miami, KS

Built 1920 Load: 26.3 t ADT: 48

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.