Total bridges
186
Public highway bridges in Marion County
County profile · official public datasets
Marion County, MO
186 public highway bridges tracked in the FHWA National Bridge Inventory: 37.1% rated Good, 53.8% Fair, 9.1% Poor.
- 186
- Public bridges
- 37.1%
- Good condition
- 9.1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Marion County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 61st
- of 115 on Poor share
- 9.1%
- Poor-condition share
- 186
- public highway bridges
- 1977
- 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 #61 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.1%). Marion County, Missouri contains 186 public highway bridges. Roughly 37.1% are rated “Good,” 53.8% “Fair,” and 9.1% “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
37.1%
69 of 186 rated 7-9
Fair condition
53.8%
100 of 186 rated 5-6
Poor condition
9.1%
17 of 186 rated 4 or below
In-state Poor-share rank
#61 of 115
Among Missouri counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 186 NBI-tracked bridges by lowest applicable component rating.
Good 37.1% (69)
Fair 53.8% (100)
Poor 9.1% (17)
Marion County's Poor-condition bridges carry 24,685 vehicle crossings a day
That is 5.2% of the county's reported daily bridge traffic on 9.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,452 crossings a day against 2,741 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 186 of 186 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
37.1% of Marion County's bridges have passed the 50-year mark
69 of the 186 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 37.1% 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 64.4% of the county's Poor-condition bridge traffic
IS 72 E over MISSISSIPPI RVR CST 410, built 2000, carries 15,906 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 17-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 24,685 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
186 bridges with a recorded construction year, grouped by decade
- 1910s 3
1910–1919
3 bridges
- 1920s 11
1920–1929
11 bridges
- 1930s
1930–1939
18 bridges
- 1940s 1
1940–1949
1 bridges
- 1950s
1950–1959
15 bridges
- 1960s 13
1960–1969
13 bridges
- 1970s
1970–1979
18 bridges
- 1980s
1980–1989
36 bridges
- 1990s
1990–1999
24 bridges
- 2000s
2000–2009
29 bridges
- 2010s
2010–2019
15 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1980s, when 36 of the county's bridges still in the inventory were built, which is 19.4% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1977) matches the Missouri average (1979).
How Marion County compares with Missouri's closest counties by inventory size
The 5 Missouri counties nearest Marion County in number of bridges, with their condition splits. Its 9.1% Poor share is the 2nd-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1976 is in line with the group.
Showing the 5 closest of 114 Missouri counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Howell County | 189 | 34.4% | 63.5% | 2.1% | 1966 |
| Grundy County | 187 | 54% | 34.8% | 11.2% | 1992 |
| Marion County (this page) | 186 | 37.1% | 53.8% | 9.1% | 1977 |
| Livingston County | 185 | 34.1% | 50.3% | 15.7% | 1978 |
| Polk County | 185 | 31.9% | 47.6% | 20.5% | 1966 |
| Ray County | 185 | 36.2% | 51.4% | 12.4% | 1977 |
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 Missouri so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MO (186 bridges here).
- Fayette County, AL · 186 bridges
- Adams County, IA · 186 bridges
- Coshocton County, OH · 186 bridges
- Montgomery County, TN · 186 bridges
Similar average build year
Nearest mean year-built outside MO (1977 here).
- San Diego County, CA · avg 1977 · 1,632 bridges
- King County, WA · avg 1977 · 1,238 bridges
- Riverside County, CA · avg 1977 · 1,117 bridges
- Shelby County, TN · avg 1977 · 1,077 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (69)
IS 72 W
GoodOver: CST CENTRAL AVE
S 19 T 57 N R 4 W, Marion, MO
Built 1993 Load: 44.1 t ADT: 7,995
US 36 E
GoodOver: CST MUNGER LN
S 24 T 57 N R 5 W, Marion, MO
Built 2003 Load: 45.9 t ADT: 5,078
US 36 W
GoodOver: CST MUNGER LN
S 24 T 57 N R 5 W, Marion, MO
Built 2003 Load: 45.9 t ADT: 5,265
COUNTY RD 312
GoodOver: BETHEL BR
S 27 T 59 N R 6 W, Marion, MO
Built 2016 Load: 45.9 t ADT: 65
RT K S
GoodOver: S FK NORTH RVR
S 29 T 57 N R 8 W, Marion, MO
Built 2018 Load: 45.9 t ADT: 126
US 24 E
GoodOver: SOUTH RVR
S 12 T 57 N R 6 W, Marion, MO
Built 2001 Load: 46.8 t ADT: 8,156
COUNTY RD 197
GoodOver: NORTH RVR
S 15 T 58 N R 8 W, Marion, MO
Built 2000 Load: 46.8 t ADT: 50
COUNTY RD 279
GoodOver: SOUTH RVR
S 10 T 57 N R 6 W, Marion, MO
Built 1999 Load: 46.8 t ADT: 50
US 24 E
GoodOver: US 36
S 31 T 57 N R 5 W, Marion, MO
Built 2001 Load: 46.8 t ADT: 2,539
COUNTRY CLUB DR S
GoodOver: IS 72
S 19 T 57 N R 4 W, Marion, MO
Built 1995 Load: 49.5 t ADT: 802
IS 72 E
GoodOver: MO 79
S 192 T 57 N R 4 W, Marion, MO
Built 1997 Load: 50.4 t ADT: 10,373
IS 72 W
GoodOver: MO 79
S 192 T 57 N R 4 W, Marion, MO
Built 1997 Load: 50.4 t ADT: 7,231
COUNTY RD 240
GoodOver: SEES CR
S 22 T 57 N R 7 W, Marion, MO
Built 2015 Load: 51.3 t ADT: 38
RT MM E
GoodOver: BEAR CR
S 28 T 57 N R 5 W, Marion, MO
Built 2012 Load: 52.2 t ADT: 3,430
US 24 W
GoodOver: BNSF RR
S 36 T 57 N R 7 W, Marion, MO
Built 1993 Load: 53.1 t ADT: 6,195
COUNTY RD 189
GoodOver: NORTH RVR
S 24 T 58 N R 8 W, Marion, MO
Built 2012 Load: 53.1 t ADT: 38
MALARUNI RD
GoodOver: SOUTH RIVER
S 29 T 58 N R 5 W, Marion, MO
Built 2021 Load: 53.1 t ADT: 250
COUNTY RD 225
GoodOver: BRANCH
S 12 T 56 N R 8 W, Marion, MO
Built 2007 Load: 96.3 t ADT: 200
COUNTY RD 411
GoodOver: BRANCH
S 26 T 58 N R 5 W, Marion, MO
Built 2003 Load: 99.9 t ADT: 50
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.