Total bridges
63
Public highway bridges in Shannon County
County profile · official public datasets
Shannon County, MO
63 public highway bridges tracked in the FHWA National Bridge Inventory: 25.4% rated Good, 63.5% Fair, 11.1% Poor.
- 63
- Public bridges
- 25.4%
- Good condition
- 11.1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Shannon 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.
- 82nd
- of 115 on Poor share
- 11.1%
- Poor-condition share
- 63
- public highway bridges
- 1961
- 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.
Shannon County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Shannon County ranks #82 of 115 Missouri counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 11.1%). Shannon County, Missouri contains 63 public highway bridges. Roughly 25.4% are rated “Good,” 63.5% “Fair,” and 11.1% “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
25.4%
16 of 63 rated 7-9
Fair condition
63.5%
40 of 63 rated 5-6
Poor condition
11.1%
7 of 63 rated 4 or below
In-state Poor-share rank
#82 of 115
Among Missouri counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 63 NBI-tracked bridges by lowest applicable component rating.
Good 25.4% (16)
Fair 63.5% (40)
Poor 11.1% (7)
Shannon County's Poor-condition bridges carry 4,256 vehicle crossings a day
That is 7.2% of the county's reported daily bridge traffic on 11.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 608 crossings a day against 832 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 63 of 63 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
61.9% of Shannon County's bridges have passed the 50-year mark
39 of the 63 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 25.4% 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 33.5% of the county's Poor-condition bridge traffic
MO 19 S over HURRICANE CR, built 1937, carries 1,426 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 7-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 4,256 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Shannon County's bridges were built
63 bridges with a recorded construction year, grouped by decade
- 1920s
1920–1929
14 bridges
- 1930s
1930–1939
8 bridges
- 1940s 5
1940–1949
5 bridges
- 1950s
1950–1959
7 bridges
- 1960s 3
1960–1969
3 bridges
- 1970s
1970–1979
6 bridges
- 1980s 4
1980–1989
4 bridges
- 1990s
1990–1999
8 bridges
- 2000s 3
2000–2009
3 bridges
- 2010s 5
2010–2019
5 bridges
What this shows Construction peaked in the 1920s, when 14 of the county's bridges still in the inventory were built, which is 22.2% of those with a recorded year. That cohort is now 95 to 104 years old in the 2024 inventory. Its average build year is 1961, 18 years older than the Missouri average of 1979.
How Shannon County compares with Missouri's closest counties by inventory size
The 5 Missouri counties nearest Shannon County in number of bridges, with their condition splits. Its 11.1% Poor share is the 4th-lowest of these 6. Its average build year of 1961 against a peer-group mean of 1971 is 10 years older.
Showing the 5 closest of 114 Missouri counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Dent County | 75 | 21.3% | 70.7% | 8% | 1969 |
| Douglas County | 75 | 18.7% | 74.7% | 6.7% | 1963 |
| Maries County | 69 | 31.9% | 52.2% | 15.9% | 1974 |
| Stone County | 64 | 50% | 43.8% | 6.3% | 1982 |
| Shannon County (this page) | 63 | 25.4% | 63.5% | 11.1% | 1961 |
| Hickory County | 57 | 38.6% | 43.9% | 17.5% | 1968 |
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 Shannon 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 Shannon County, both outside Missouri so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside MO (63 bridges here).
- Highlands County, FL · 63 bridges
- Chattahoochee County, GA · 63 bridges
- Red River County, LA · 63 bridges
- Lincoln County, ME · 63 bridges
Similar average build year
Nearest mean year-built outside MO (1961 here).
- Westchester County, NY · avg 1961 · 774 bridges
- Tehama County, CA · avg 1961 · 450 bridges
- Berkshire County, MA · avg 1961 · 450 bridges
- Schuylkill County, PA · avg 1961 · 368 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (7)
RT JJ S
PoorOver: CASTRO VALLEY
S 6 T 29 N R 6 W, Shannon, MO
Built 1959 Load: 9.9 t ADT: 929
COUNTY RD 568
PoorOver: PIKE CR
S 23 T 27 N R 3 W, Shannon, MO
Built 1950 Load: 10.8 t ADT: 10
MO 99 S
PoorOver: SPRING CR
S 20 T 26 N R 5 W, Shannon, MO
Built 1934 Load: 14.4 t ADT: 530
MO 19 S
PoorOver: HURRICANE CR
S 31 T 16 N R 2 W, Shannon, MO
Built 1937 Load: 15.3 t ADT: 1,426
MO 19 S
PoorOver: RND SPRGCAV RD PRK SP
S 20 T 30 N R 4 W, Shannon, MO
Built 1930 Load: 17.1 t ADT: 416
MO 106 E
PoorOver: SPRING VALLEY CR
S 20 T 29 N R 6 W, Shannon, MO
Built 1941 Load: 17.1 t ADT: 604
MO 106 E
PoorOver: CURRENT RIVER
S 16 T 29 N R 2 W, Shannon, MO
Built 1973 Load: 35.1 t ADT: 341
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.