County profile · official public datasets

Marion County, KS

324 public highway bridges tracked in the FHWA National Bridge Inventory: 39.2% rated Good, 51.2% Fair, 9.6% Poor.

324
Public bridges: 39.2%
Good condition: 9.6%
Poor condition

The verdict

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

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

88th
of 104 on Poor share: 9.6%
Poor-condition share: 324
public highway bridges: 1959
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 #88 of 104 Kansas counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.6%). Marion County, Kansas contains 324 public highway bridges. Roughly 39.2% are rated “Good,” 51.2% “Fair,” and 9.6% “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

324

Public highway bridges in Marion County

Good condition

39.2%

127 of 324 rated 7-9

Fair condition

51.2%

166 of 324 rated 5-6

Poor condition

9.6%

31 of 324 rated 4 or below

In-state Poor-share rank

#88 of 104

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

Condition distribution

Share of 324 NBI-tracked bridges by lowest applicable component rating.

Good

39.2% (127)

Fair

51.2% (166)

Poor

9.6% (31)

Marion County's Poor-condition bridges carry 1,090 vehicle crossings a day

That is 0.7% of the county's reported daily bridge traffic on 9.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 35 crossings a day against 924 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 324 of 324 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

62.7% of Marion County's bridges have passed the 50-year mark

203 of the 324 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 39.2% 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 14.7% of the county's Poor-condition bridge traffic

60 RD. over TRIB. TO DOYLE CREEK, built 1935, carries 160 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 31-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 1,090 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

pre-1900

1
1900s

3
1910s

13
1920s

32
1930s

70
1940s

39
1950s

13
1960s

21
1970s

19
1980s

35
1990s

33
2000s

37
2010s

7
2020s

1

What this shows Construction peaked in the 1930s, when 70 of the county's bridges still in the inventory were built, which is 21.6% of those with a recorded year. That cohort is now 85 to 94 years old in the 2024 inventory. Its average build year is 1959, 13 years older than the Kansas average of 1972.

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

The 5 Kansas counties nearest Marion County in number of bridges, with their condition splits. Its 9.6% Poor share is the 6th-lowest of these 6. Its average build year of 1959 against a peer-group mean of 1972 is 13 years older.

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

Bridge inventory size and condition shares for Marion County and the 5 Kansas counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Franklin County	332	55.1%	40.7%	4.2%	1972
Miami County	326	64.7%	31.9%	3.4%	1974
Montgomery County	326	32.2%	62.3%	5.5%	1969
Marion County (this page)	324	39.2%	51.2%	9.6%	1959
Cherokee County	317	42.6%	53%	4.4%	1967
Wyandotte County	315	62.5%	34.6%	2.9%	1980

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

Similar inventory size

Nearest county inventories outside KS (324 bridges here).

Limestone County, AL · 324 bridges
Merrimack County, NH · 326 bridges
Washington County, OR · 326 bridges
White County, AR · 322 bridges

Similar average build year

Nearest mean year-built outside KS (1959 here).

Tulare County, CA · avg 1959 · 589 bridges
Nassau County, NY · avg 1959 · 328 bridges
Hampshire County, MA · avg 1959 · 259 bridges
Noble County, OH · avg 1959 · 208 bridges

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

All 324 Good 127 Fair 166 Poor 31

Good-condition bridges (127)

Sort:

Marion County Bridge Snapshot

Condition distribution

Marion County's Poor-condition bridges carry 1,090 vehicle crossings a day

62.7% of Marion County's bridges have passed the 50-year mark

One structure carries 14.7% of the county's Poor-condition bridge traffic

How Marion County compares with Kansas'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 (127)

US-50 HWY

370 RD.

INDIGO RD.

330 RD.

ZEBULON RD.

LIMESTONE RD.

360 RD.

120 RD.

NIGHTHAWK RD.

330 RD.

330 RD.

KANZA RD.

ZEBULON RD.

320 RD.

250 RD.

GOLDENROD RD.

BLUESTEM RD.

330 RD.

300 RD.

US-77 HWY

DIAMOND RD.

DIAMOND RD.

INDIGO RD.

XAVIER RD.

US-77 HWY

NIGHTHAWK RD.

210 RD.

K256 HWY

K150 HWY

360 RD.

150 RD.

US-50 HWY

US56 HWY

FALCON RD.

30 RD.

US-50 HWY

REMINGTON RD.

PAWNEE RD.

K150 HWY

80 RD.

US-77 HWY

XAVIER RD.

OLD MILL RD.

170 RD.

270 RD.

290 RD.

INDIGO RD.

MERDIAN RD.

REMINGTON RD.

270 RD.

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