Total bridges
324
Public highway bridges in Marion County
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.
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.
When Marion County's bridges were built
324 bridges with a recorded construction year, grouped by decade
- pre-1900 1
Built before 1900
1 bridges
- 1900s 3
1900–1909
3 bridges
- 1910s 13
1910–1919
13 bridges
- 1920s
1920–1929
32 bridges
- 1930s
1930–1939
70 bridges
- 1940s
1940–1949
39 bridges
- 1950s 13
1950–1959
13 bridges
- 1960s 21
1960–1969
21 bridges
- 1970s 19
1970–1979
19 bridges
- 1980s
1980–1989
35 bridges
- 1990s
1990–1999
33 bridges
- 2000s
2000–2009
37 bridges
- 2010s 7
2010–2019
7 bridges
- 2020s 1
2020–2029
1 bridges
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.
| 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.
Fair-condition bridges (166)
290 RD.
FairOver: TRIB. N. COTTONWOOD RIV.
0.5N 3.1W OF DURHAM, Marion, KS
Built 1981 Load: 32.2 t ADT: 95
270 RD.
FairOver: TRIB. TO CLEAR CREEK
2.0S 0.5W OF LINCOLNVILLE, Marion, KS
Built 1995 Load: 32.2 t ADT: 40
FALCON RD.
FairOver: SOUTH COTTONWOOD RIVER
2.3S 3.0W OF HILLSBORO, Marion, KS
Built 1981 Load: 32.4 t ADT: 40
70 RD.
FairOver: DOYLE CREEK
11.5S 0.2E OF HILLSBORO, Marion, KS
Built 1981 Load: 32.4 t ADT: 20
OLD MILL RD.
FairOver: SOUTH COTTONWOOD RIVER
0.8S 0.9E OF CANADA, Marion, KS
Built 2002 Load: 32.9 t ADT: 35
XAVIER RD.
FairOver: TRIB. TO SPRING CREEK
3.4S OF FLORENCE, Marion, KS
Built 1940 Load: 33.9 t ADT: 45
GOLDENROD RD.
FairOver: TRIB. TO N. COTTONWOOD
0.6W 1.0S OF DURHAM, Marion, KS
Built 1986 Load: 34.1 t ADT: 20
US-50 HWY
FairOver: COTTONWOOD RIVER
1.19 MI E US-77, Marion, KS
Built 1995 Load: 34.4 t ADT: 4,200
US56 HWY
FairOver: MUD CR UP RR WALNUT ST
0.83 MI E K256, Marion, KS
Built 1987 Load: 34.5 t ADT: 3,090
FALCON RD.
FairOver: FRENCH CREEK
2.5W 3.1N OF HILLSBORO, Marion, KS
Built 1999 Load: 35.4 t ADT: 35
230 RD.
FairOver: CLEAR CREEK
3.2N 0.9E OF MARION, Marion, KS
Built 2000 Load: 35.7 t ADT: 20
190 RD.
FairOver: SOUTH COTTONWOOD RIVER
3.0W OF MARION, Marion, KS
Built 1980 Load: 40.2 t ADT: 2,140
LIMESTONE RD.
FairOver: ANTELOPE CREEK
2.3E 1.9S OF HILLSBORO, Marion, KS
Built 1994 Load: 47.5 t ADT: 30
US56 HWY
FairOver: CLEAR CREEK
7.44 MI N US77 SJCT, Marion, KS
Built 1986 Load: 60.8 t ADT: 2,440
MUSTANG RD.
FairOver: SOUTH COTTONWOOD RIVER
3.3E 1.1S OF HILLSBORO, Marion, KS
Built 2004 Load: 72.0 t ADT: 35
280 RD.
FairOver: TRIB. TO MUD CREEK
0.5N 2.6W OF PILSEN, Marion, KS
Built 2003 Load: 89.8 t ADT: 20
Read our methodology - how this data is sourced, computed, and verified.
Related
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.